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Conference 13096
Ground-based and Airborne Instrumentation for Astronomy X
16 - 20 June 2024
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Session 1:
Instruments Overview of Existing Large Facilities I
16 June 2024 • 08:30 - 10:00 Japan Standard Time
Session Chair:
Kentaro Motohara, National Astronomical Observatory of Japan (Japan)
13096-1
Current and future instrumentation at Gemini Observatory
(Invited Paper)
16 June 2024 • 08:30 - 09:00 Japan Standard Time
Show Abstract +
The Gemini Observatory instrument program supports breakthrough research in areas like extrasolar planets, time domain astrophysics, dark matter and dark energy, with the best possible competitive instrumentation suite given technological and budget constraints. This talk will give a broad overview of Gemini's instrumentation program focusing on achievements, challenges, and strategies. We report on the status of the currently offered facility instruments and AO systems at each telescope as well as on newly commissioned instruments and ongoing projects.
13096-2
Instrumentation at the Subaru Telescope
(Invited Paper)
16 June 2024 • 09:00 - 09:30 Japan Standard Time
Show Abstract +
We present the current status and future plan of the instruments at the Subaru Telescope.
The Prime Focus Spectrograph (PFS) achieved the engineering first light in September, 2022.
The installation of the PFS subsystems will be completed in November, 2023, and it is
entering the final stage of the commissioning. For the next generation wide-field facility
instrument ULTIMATE-Subaru, it successfully passed the preliminary design review and started
the detailed design study for the GLAO system in 2022. There are ongoing projects for the
facility AO system (AO188) including the upgrades of the deformable mirror and wavefront
sensors. In addition, we are discussing implementations of the Nasmyth Beam Switcher, which
enables remotely switching the instruments downstream of AO188, for more efficient operation
at NsIR focus. As for the visitor instruments, there are a growing number of interests to
carry in new instruments, upgrade existing ones, or resume operations of decommissioned
instruments as visitor instruments. We are having discussions to better coordinate these
demands and develop a future roadmap of NsIR instrumentation including both facility and
visitor instruments.
13096-3
The Paranal Instrumentation Programme at ESO
(Invited Paper)
16 June 2024 • 09:30 - 10:00 Japan Standard Time
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For more a decade the Paranal Instrumentation programme at ESO is responsible for the procurement and ddelivery of the instruments to the VLT and La Silla observatories. We will review the status of the programme, the most recent instruments delivered, with a glimpse to the future. CRIRES+, ERIS, NIRPS have been recently added to the battery of instrument offered, and four major projects: MOONS, 4MOST, SoXS and GRAVITY+ are close to the start of operations.
Break
Coffee Break 10:00 - 10:20
Session 2:
Instruments Overview of Existing Large Facilities II
16 June 2024 • 10:20 - 12:20 Japan Standard Time
Session Chair:
Joël D.R. Vernet, European Southern Observatory (Germany)
13096-4
16 June 2024 • 10:20 - 10:50 Japan Standard Time
Show Abstract +
This presentation will provide a status report for the Large Binocular Telescope Observatory instrument program, including recent and planned upgrades for first-generation optical spectrographs MODS and PEPSI, and early results and performance of the second generation systems.
The Observatory is in the process of commissioning a cohort of new instruments that leverage the LBT’s advanced AO capability for study of exoplanets and similar sources. These additions include the SHARK-VIS and SHARK-NIR instruments for high-contrast, high-resolution imaging and coronography in the visible and near-infrared bandpasses, respectively, with spectroscopic capability available also in the near-IR system. A third instrument, the iLocater diffraction-limited spectrograph offering extremely high precision radial velocities, is scheduled for delivery in 2024.
13096-17
Prime Focus Spectrograph (PFS) for Subaru Telescope: progressing final steps to science operation
(Invited Paper)
16 June 2024 • 10:50 - 11:20 Japan Standard Time
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The PFS (Prime Focus Spectrograph) instrumentation is nearly complete finally. The only missing hardware is the last two spectrograph modules, but the installations are ongoing well as of this abstract being written and are expected to complete very soon. On-sky engineering tests and observations have been carried out continually since September 2021 and, after the resolutions of some major issues on hardware and software, the team successfully observed many targeted stars over the entire field of view (Engineering First Light) in September 2022. The performances and operation of the instrument are being optimized e.g. in the accuracy and speed of fiber positioning process. Long integrations of relatively faint objects are being taken to validate expected increase of signal-to-noise ratio. Given the science operation will start soon after the commissioning process is complete, various procedures of proposing, planning, & executing observations, processing data & assessing their qualities, and delivering data to observers are being developed and tested. In this contribution, a top-level summary of these achievements and ongoing progresses and future perspectives will be provided.
13096-6
16 June 2024 • 11:20 - 11:50 Japan Standard Time
Show Abstract +
Since the start of science operations in 1993, the twin 10-meter W. M. Keck Observatory (WMKO) telescopes have continued to maximize their scientific impact to produce transformative discoveries that keep the U.S. observing community on the frontiers of astronomical research. Upgraded capabilities and new instrumentation are provided though collaborative partnerships primarily with the Caltech and University of California instrument development teams and through additional collaborations with the University of Notre Dame, the University of Hawaii, Swinburne University of Technology, industry, and other organizations. This paper summarizes the status and performance of observatory infrastructure projects, technology upgrades, and new additions to the suite of observatory instrumentation. We also provide a status of instrumentation projects in early and advanced stages of development that will achieve the goals and objectives summarized in the 2023 Keck Observatory strategic plan. Developed in collaboration with the WMKO science community, the Keck strategic plan sets our sites on 2035 and meets goals identified in the Astro2020 Decadal Survey.
13096-7
Southern African Large Telescope (SALT) instrumentation update
(Invited Paper)
16 June 2024 • 11:50 - 12:20 Japan Standard Time
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The Southern African Large Telescope (SALT) is a 10m class fixed-elevation telescope with a primary mirror composed of 91 spherically figured one metre segments. A prime focus tracker assembly carries the spherical aberration corrector and two of SALT’s instruments, SALTICAM (the telescope’s acquisition and imaging camera) and the multi-purpose Robert Stobie spectrograph (RSS). Included in the payload is the fibre-instrument feed, that positions ~45m long fibre cables coupled to spectrographs housed in thermal enclosures beneath the telescope. These are the High-Resolution Spectrograph (HRS) and NIRWALS (Near InfraRed Washburn Astronomical Laboratories Spectrograph), the latter having a 29” x 18” flattened-hexagon shaped fibre integral field unit. NIRWALS is the latest addition to the SALT instrument suite and the other major development is a custom-built laser frequency comb and precision radial velocity data pipeline for the High Stability mode of HRS, due to be available in early 2025. Work is also underway to develop a new calibration system to serve the full 320-1700nm wavelength range of the telescope, and a new red channel will turn the RSS into a dual-beam spectrograph.
Break
Lunch Break 12:20 - 13:40
Session 3:
High-dispersion Spectrographs I
16 June 2024 • 13:40 - 15:30 Japan Standard Time
Session Chair:
Joël D.R. Vernet, European Southern Observatory (Germany)
13096-8
IGRINS-2 for Gemini Telescope: development and early performance
(Invited Paper)
16 June 2024 • 13:40 - 14:10 Japan Standard Time
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IGRINS-2 is a high-resolution, near-infrared spectrograph developed by Korea Astronomy and Space Science Institute (KASI) for Gemini Observatory as a new facility instrument. It provides spectral resolving power of ~45,000 and a simultaneous wavelength coverage of 1.49-2.46 μm. IGRINS-2 is an improved version of IGRINS (Immersion GRating INfrared Spectrometer) with minor optical and mechanical design changes, new detector controllers, and operating software to be fully integrated into Gemini operating systems. Since the project began in early 2020, project key milestones including critical design review, fabrication, assembly and pre-delivery performance verification were completed, and IGRINS-2 was delivered to Gemini North in early September, 2023. After the successful post-delivery verification and telescope integration, the first light spectra were acquired in October 2023. We present design changes and upgrades made to IGRINS-2 from the original IGRINS, assembly and alignment procedures, and verification of the instrument requirements. We also report the preliminary results of the system performance tests.
Show Abstract +
The Keck Planet Finder (KPF) is a fiber-fed, high-resolution, high-stability spectrometer specifically designed to characterize exoplanets using Doppler spectroscopy. KPF was installed and commissioned at the W. M. Keck Observatory in late 2022. The instrument includes a green channel (445 nm to 600 nm) and red channel (600 nm to 870 nm), and achieves a resolving power of ~95,000 and a Doppler precision of less than 0.5 m s−1. A novel design aspect of the KPF spectrometer is the use of a Zerodur optical bench, and Zerodur optics with integral mounts, to provide stability against thermal expansion and contraction effects. Here we will present an overview of the KPF instrument and also report on its on-sky performance.
13096-10
16 June 2024 • 14:30 - 14:50 Japan Standard Time
Show Abstract +
Laser frequency combs, producing a dense grid of equidistant optical emission lines, are considered the best calibration sources for precision astronomical spectrographs. The recently commissioned Near-Infra-Red Planet Searcher (NIRPS), operating at the 3.6m telescope in La Silla, Chile, will be equipped with an astrocomb for the wavelength calibration in the 1200nm – 1850nm range. The astrocomb is based on the electro-optic modulation technology and offers tunability of the full optical spectrum.
13096-11
16 June 2024 • 14:50 - 15:10 Japan Standard Time
Show Abstract +
A major endeavor of this decade is the direct characterization of young giant exoplanets at high spectral resolution to determine the composition of their atmosphere and infer their formation processes and evolution. We present the implementation and first on-sky results of the HiRISE instrument at the very large telescope (VLT), which combines the exoplanet imager SPHERE with the recently upgraded high resolution spectrograph CRIRES using single-mode fibers. After introducing the global implementation, we will present the status after commissioning and after the first science observing runs. We will, in particular, focus on the performance and th lessons learned during the development, installation and validation.
13096-12
16 June 2024 • 15:10 - 15:30 Japan Standard Time
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The Near Infra Red Planet Searcher (NIRPS) is a precision radial velocity spectrograph developed through collaborative efforts among laboratories in Brazil, Canada, France, Portugal, Spain, and Switzerland. NIRPS extends to the 0.98-1.8µm domain the pioneering HARPS instrument at the La Silla 3.6-m telescope and it has achieved unparalleled precision, measuring stellar radial velocities in the infrared with accuracy better than 1 m/s.
Commissioned in late 2022 and early 2023, NIRPS embarked on a 5-year Guaranteed Time Observation (GTO) program in April 2023, spanning 720 observing nights. This program focuses on planetary systems around M dwarfs, encompassing both the immediate solar vicinity and transit follow-ups, alongside transit and emission spectroscopy observations. We will provide a comprehensive review of the NIRPS instrument, highlighting its current performance and sharing valuable insights gained during its deployment at the telescope. The lessons learned and successes achieved contribute to the ongoing advancement of precision radial velocity measurements and high spectral fidelity, further solidifying NIRPS’ role in the forefront of exoplanetary exploration.
Break
Coffee Break 15:30 - 16:00
Session 4:
IFS I
16 June 2024 • 16:00 - 17:30 Japan Standard Time
Session Chair:
Livia Origlia, INAF - Osservatorio di Astrofisica e Scienza dello Spazio (Italy)
13096-13
Hector: performance of the new integral field spectrograph instrument for the Anglo-Australian Telescope
(Invited Paper)
16 June 2024 • 16:00 - 16:30 Japan Standard Time
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The capacity for large IFS nearby galaxy surveys on the Anglo-Australian Telescope (AAT) has just been substantially expanded with the commissioning now complete for a new instrument, Hector. Hector, built by Astralis - Australia's Astronomical Instrumentation Consortium, has 21 new optical fibre imaging bundles `hexabundles’ over a 2-degree field. It consists of new blue and red-arm spectrographs, coupled to the hexabundles and a novel robotic positioning concept which compensates for varying telecentricity. The Hector Galaxy Survey began in 2023 and has now begun taking IFS cubes of 15,000 galaxies in the Hector Galaxy Survey. The performance of the Hector instrument based on the early science data will be presented along with an overview of the instrument subsystems and lessons learned.
13096-14
16 June 2024 • 16:30 - 16:50 Japan Standard Time
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The Visible Integral Field Replicable Unit Spectrograph (VIRUS) was designed to conduct the Hobby Eberly Telescope Dark Energy Experiment (HETDEX) that will build an unprecedented sample of nearly 1 million Lyman Alpha Emitting galaxies from a 1.9< z<3.5 purely via spectroscopic selection. VIRUS is the first astrophysics instrument to utilize massive replication on a 100-fold scale enabling its novel ability to conduct integral field spectroscopy over large areas of the sky. VIRUS consists of 156 realizations of the same spectrograph allowing it to image nearly 35K spectra with each observation. This design takes advantage of large-scale replication of simple units to significantly reduce engineering and production. This proceeding analyses the statistical variations in performance of these units and discusses the lessons learned and strategies for optimizing the cost saving and risk for instrument designs that take advantage of large-scale replication. We present VIRUS as a proof of concept that massively replicated instruments provide a viable solution to scaling up instrument capability for the next generation of large surveys and telescopes.
13096-15
16 June 2024 • 16:50 - 17:10 Japan Standard Time
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VIRUS2 is a new NSF-funded fiber-fed multiplexed integral field spectrograph consisting of 6 units, each with 4 spectral channels, providing large on-sky area coverage coupled with broad spectral coverage (370-930 nm at R~2000). On the McDonald Observatory 2.7 m Harlan J Smith Telescope, VIRUS2 will cover a 1.7 by 1.3 = 2.3 sq. arcmin. field of view, with full fill-factor. VIRUS2 employs a novel beam-switch module (BSM) within the fiber feed to split the light into the 4 spectral channels. The novel design of VIRUS2 emphasizes stability and careful calibration, with scrambling in the BSM, compact spectrograph format, and tight thermal control.
Science drivers for VIRUS2 are resolved studies of nearby galaxies, their circum-galactic environments, and their dark matter content, blind spectroscopic surveys and transients. we provide an overview of the instrument and describe the assembly and present early results from commissioning.
13096-16
16 June 2024 • 17:10 - 17:30 Japan Standard Time
Show Abstract +
We present the overall design, fabrication status, and key science drivers of the next-generation W. M. Keck Observatory Adaptive Optics (AO) near-infrared (0.8 - 2.45 micron) integral field spectrograph (IFS) and imaging camera, named Liger. The Liger team has completed its Final Design Phase and entered the Fabrication phase. Liger offers excellent sensitivity with significant improvements in wavelength coverage enabling a broad range of new science. Liger will provide unique capabilities with higher resolution spectroscopy (R=4000 - 10,000), extending to bluer wavelengths (< 1 micron), and a larger field of view than other AO-fed IFS. We will present the status of the program, fabrication efforts, and focus on the most challenging aspects of the design and execution of the instrument.
Monday Plenary Session
17 June 2024 • 08:30 - 10:00 Japan Standard Time
Join us for the Monday morning plenary talks.
Break
Coffee Break 10:00 - 10:20
Session 5:
Multi Object Spectrographs I
17 June 2024 • 10:20 - 11:50 Japan Standard Time
Session Chair:
Julia . Bryant, The Univ. of Sydney (Australia)
13096-5
The instrumentation plan of the 10.4m GTC telescope
(Invited Paper)
17 June 2024 • 10:20 - 10:50 Japan Standard Time
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The 10.4m Gran Telescopio Canarias (GTC) was designed to be a versatile telescope, able to serve a wide scientific community. To this aim, various focal stations have been equipped, including a Cassegrain, two Nasmyth foci, and four folded-Cassegrain stations. This allows an ambitious instrumentation plan to be developed. We will present the latest developments and plans, with emphasis on the most relevant and innovative features. They include: new detectors and cryogenic (pulse tube) systems for the main GTC instruments, the migration of the HiPERCAM imager on a dedicated focus with an ad-hoc rotator; the commissioning of a single-conjugated, AO system; the preparation to host in the Coudé room a fibre-fed UV and optical spectrograph which aims at a 10cm/s radial velocity stability; and the plan for the future instruments, which include the upgrading of AO and an imager and spectrograph covering simultaneously the optical and near-infrared domains.
13096-18
17 June 2024 • 10:50 - 11:10 Japan Standard Time
Show Abstract +
Ocotillo is a new fiber-fed optical spectrograph being built for the Apache Point Observatory ARCS 3.5m telescope. The spectrograph consists of three channels, observing from the very blue to near the infrared, across the full optical bandpass. It is a relatively low resolution spectrograph, with ~2000 < R < 4000, depending on wavelength. There are two interchangable fiber feeds - one, a single integral field unit. The second fiber feed is a collection of robotic fiber positioners, each carrying 19 fibers in a small integral field unit. The fiber run has a single connector between the front end and the spectrograph slit, making for a straight forward swap between the two assemblies. We present here the overall opto-mechanical design and progress towards commissioning.
13096-19
17 June 2024 • 11:10 - 11:30 Japan Standard Time
Show Abstract +
4MOST is a new high-multiplex, wide-field spectroscopic survey facility under construction for ESO's 4m-VISTA telescope at Paranal, Chile. Its key specifications are: a large field of view of 4.4 square degrees, a high multiplex fibre positioner based on the tilting spine principle positioning 2436 science fibres, 1624 fibres going to two low-resolution spectrographs (R = λ/Δλ ~ 6500), and 812 fibres transferring light to the high-resolution spectrograph (R ~ 20,000). The instrument is entirely completed and is being shipped to Paranal Observatory, Chile in the first few months of 2024. Commissioning will take place summer 2024 with full operations expected to start early 2025. An overview will be given of instrument capabilities, the planned, and the unique operational scheme of 4MOST.
13096-20
17 June 2024 • 11:30 - 11:50 Japan Standard Time
Show Abstract +
The Gemini Infrared Multi-Object Spectrograph (GIRMOS) is a new facility instrument being designed in close partnership with the upcoming facility adaptive optics (AO) system at Gemini-North observatory called GNAO. GIRMOS will carry out high angular resolution (0.9 – 2.4 µm) imaging and multi-object integral field (0.95 – 2.35 µm) spectroscopy within GNAO’s two arcminute field-of-regard. GIRMOS consists of an imager and four identical deployable integral field spectrographs with a multi-object AO system that provides an additional image quality improvement for each spectrograph over GNAO across the full field. We present the final design overview of GIRMOS, which will be entering the construction phase in 2024 with an expected delivery in 2027. GIRMOS is a pathfinder for future extremely large telescope instrumentation that requires high angular resolution, highly multiplexed spectroscopy.
Break
Lunch Break 11:50 - 13:10
Session 6:
Instruments with New Concept/Technologies I
17 June 2024 • 13:10 - 15:30 Japan Standard Time
Session Chair:
Shelley A. Wright, Univ. of California, San Diego (United States)
13096-24
17 June 2024 • 13:10 - 13:30 Japan Standard Time
Show Abstract +
Arrayed waveguide gratings (AWGs) are gaining attention for use in earthbound telescopes, airborne applications, and spaceborne instruments due to their low mass, diffraction-limit properties, thermal stability, and resistance to vibrations and misalignment. The Potsdam Arrayed Waveguide Spectrograph (PAWS) is an integrated photonic spectrograph optimized for the H-Band in astronomy that utilizes a second-generation AWG as its primary component, offering exceptional spectral resolution and throughput. The dispersed light from the AWG is magnified by a microscope objective, then passed through a free-space optical system and a diffractive grating. The echellogram is focused on an H2RG near-infrared array. PAWS has been successfully validated with various light sources including an in-house developed frequency comb system, and ongoing measurements have identified parameters for future optimization and miniaturization. PAWS represents a pioneering advancement in integrated photonic spectrograph technology for astronomy.
13096-21
ORCAS Keck instrument development
(Invited Paper)
17 June 2024 • 13:30 - 14:00 Japan Standard Time
Show Abstract +
The the Orbiting Configurable Artificial Star (ORCAS) mission in collaboration with the W. M. Keck Obser-
vatory (WMKO) have designed, assembled, built and delivered within 180 days ORKID (The ORCAS Keck
Instrument Development), an early visible-wavelength performance demonstration with the Keck II Adaptive
Optics (AO) system. The optical performance of ORKID meets the technical requirements derived from science
goals of having a Nyquist sampled point spread function (PSF) at 650 nm. This is achieved by diffraction-limited
as-built performance with an RMS wavefront error below 50 nm. We show ORKID has acquired, with a closed
AO loop, no frame selection, while shifting and adding, the sharpest ever on sky image captured at Keck II
and a FWHM of 15.2 mas, the equivalent of a 9-meter space telescope, and arguably the sharpest image ever
captured by a single telescope at 650 nm. By doing so we have demonstrated the immense potential of the
Hybrid observatory ORCAS mission
13096-22
17 June 2024 • 14:00 - 14:30 Japan Standard Time
Show Abstract +
WST – Wide-field Spectroscopic Telescope: We summarise the design challenges of instrumentation for a proposed 12m class Telescope that aims to provide a large (>2.5 square degree) field of view and enable simultaneous Multi-object (> 20,000 objects) and Integral Field spectroscopy (inner 3x3 arcminutes field of view), initially at visible wavelengths. For the MOS mode, instrumentation includes the fibre positioning units, fibre runs and the high (R~40,000) and low (R~3,000 - 4,000) resolution spectrographs. For the MUSE like Integral Field Spectrograph, this includes the relay from the Telescope Focal Plane, the multi-stage splitting and slicing and almost 150 identical spectrographs. We highlight the challenge of mass production at a credible cost and the issues of maintenance and sustainable operation.
13096-23
17 June 2024 • 14:30 - 14:50 Japan Standard Time
Show Abstract +
FIRST (Fibered Imager foR a Single Telescope instrument) is a post-AO instrument that enables high-contrast imaging and spectroscopy at spatial scales below the diffraction limit. FIRST achieves sensitivity and accuracy through a unique combination of sparse aperture masking, spatial filtering by single-mode fibers and cross-dispersion in the visible. On-sky commissioning data taken with the instrument installed on the SCExAO platform at the 8-m Subaru telescope show the detection of several stellar companions, including two binary systems with an angular separation of 0.6 λ/D (11mas). Even at such a close separation, FIRST delivers information on the companion spectrum, providing valuable constraints on the stellar parameters, such as the effective temperatures and surface gravity. As a spectro-interferometer fed by a highly effective AO system such as SCExAO, FIRST offers unique capabilities in the context of the spectral characterization of close companions. The discussion concludes with insights into the future of the FIRST instrument, with the move to visible photonic technologies and further advancements in the instrument's capabilities to detect newly formed exoplanets.
13096-25
17 June 2024 • 14:50 - 15:10 Japan Standard Time
Show Abstract +
A Photonic Lantern (PL) is a novel device that efficiently converts a multi-mode fiber into several single-mode fibers. When coupled with an extreme adaptive optics (ExAO) system and a spectrograph, PLs enable high throughput spectroscopy at high angular resolution. The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system of the Subaru Telescope recently acquired a PL that converts its multi-mode input into 19 single-mode outputs. The single mode outputs feed a R~4,000 spectrograph optimized for the 600 to 760 nm wavelength range. We present here the integration of the PL on SCExAO, and study the device performance in terms of throughput, field of view, and spectral reconstruction. We also present the first on-sky demonstration of a Visible PL coupled with an ExAO system, showing a significant improvement of x12 in throughput compared to the use of a sole single-mode fiber. This work paves the way towards future high throughput photonics instrumentation at small angular resolution.
13096-26
17 June 2024 • 15:10 - 15:30 Japan Standard Time
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We present results from on-sky demonstration of a photonic Quantum-Inspired Imager (QI2) providing source reconstruction below the optical/NIR diffraction limit through atmospheric turbulence without adaptive optics. Our group has demonstrated a photonic spatial mode sorter quantum-sensing device in practice — a photonic lantern — with capabilities in both spatial and spectral diversity, as well as future extensions to polarization sensitivity. Our team has developed high-efficiency photonic lantern mode-sorting/multiplexing devices fabricated in optical fibers. Our proposed passive imaging system is therefore based on three main innovations: (i) photonic lantern spatial mode sorters with spatial and spectral diversity, (ii) atmospheric blur removal enabled by mode-/wavelength-resolution, (iii) quantum-inspired image reconstruction techniques. We present the first demonstration of this capability for astronomical observations, and explore potential future applications.
Break
Coffee Break 15:30 - 16:00
Session 7:
Multi Object Spectrographs II
17 June 2024 • 16:00 - 17:10 Japan Standard Time
Session Chair:
Julia . Bryant, The Univ. of Sydney (Australia)
13096-27
MOONS: Multi Object spectroscopy for the VLT: overview and final instrument performance ahead of commissioning
(Invited Paper)
17 June 2024 • 16:00 - 16:30 Japan Standard Time
Show Abstract +
The Multi Object Optical and Near-infrared Spectrograph (MOONS) instrument is the next generation multi-object spectrograph for the Very Large Telescope (VLT). The instrument combines the high multiplexing capability offered by 1000 optical fibres deployed by individual robotic positioners with a novel spectrograph able to provide both low- and high-resolution spectroscopy simultaneously across the wavelength range 0.64μm - 1.8μm. Powered by the collecting area of the 8-m VLT, MOONS will provide the astronomical community with a world-leading facility able to serve a wide range of Galactic, Extragalactic and Cosmological studies. This paper will provide an updated overview of the instrument and report on its performance during the final stage of integration testing. The next stage of the instrument is on site-assembly into the telescope, ready for first light and full commissioning. MOONS will be starting science operations in October 2025.
13096-28
17 June 2024 • 16:30 - 16:50 Japan Standard Time
Show Abstract +
The SOAR Adaptive-Module Optical Spectrograph (SAMOS) is a digital micromirror device (DMD)-based multi-object spectrograph and imager designed for use with the SOAR adaptive module (SAM) ground-layer adaptive optics system. SAMOS covers a wavelength range of 4000 Å to 9500 Å with a 3 x 3 arc-minute field of view. The unique layout of the instrument allows for the spectroscopic and imaging channels to operate simultaneously with the same field. While integrating spectral targets, the user can perform photometry in parallel on the remaining targets, improving the science throughput compared to a conventional multi-object spectrograph. In SAMOS, the DMD is used as a reconfigurable slit mask that redistributes slits near-instantaneously. The spectrograph operates in a low resolution mode (R ≈ 3000) and a high resolution mode (red grism R ≈ 8000 and blue grism R ≈ 10000). We demonstrate the ability of SAMOS to perform crowded-field spectroscopy by observing NGC 3105, a young open cluster in the Milky Way. We report on the instrument throughput and image quality using laboratory measurements and on-sky data with the SOAR 4.1 meter telescope.
13096-29
An update on the design and construction of the Magellan InfraRed Multi-Object Spectrograph (MIRMOS)
17 June 2024 • 16:50 - 17:10 Japan Standard Time
Show Abstract +
The Magellan Infrared Multi-object Spectrograph (MIRMOS) is a new near-infrared (NIR) multi-object spectrograph (MOS) and integral field unit (IFU) to be deployed at the Magellan 6.5-meter telescopes at Las Campanas Observatory. MIRMOS will be uniquely capable of faint optical spectroscopy over the full NIR spectrum from 0.89-2.4 micron simultaneously on a large telescope. It incorporates a R~3700 spectrograph fed by either a mechanical slit mask capable of deploying 92 slits over a 13'×3' field or an image slicer IFU with an unprecedented 26"×20" field. This is achieved through novel technologies such as a dichroic tree design for wide wavelength coverage, fast f/1.5 cameras for a large field of view; low-scatter volume-phase holographic (VPH) gratings to reduce the interline background; and a removable diffuser to realize near Poisson-limited spectrophotometric precision. MIRMOS's broad field of view and unparalleled simultaneous wavelength coverage offers a significantly faster survey rate than current instruments. MIRMOS is currently in the preliminary design phase at Carnegie Observatories and The Johns Hopkins Instrument Development Group.
Tuesday Plenary session
18 June 2024 • 08:30 - 10:00 Japan Standard Time
Join us for the Tuesday morning plenary talks.
Break
Coffee Break 10:00 - 10:20
Session 8:
Instruments for Extremely Large Telescopes I
18 June 2024 • 10:20 - 12:00 Japan Standard Time
Session Chair:
Friedrich Wöger, National Solar Observatory (United States)
13096-31
18 June 2024 • 10:20 - 10:50 Japan Standard Time
Show Abstract +
The Thirty Meter Telescope (TMT) is designing three science instruments for first light: IRIS
(InfraRed Imaging Spectrograph), WFOS (Wide Field Optical Spectrograph), and MODHIS (Multi-
Objective Diffraction-limited High-resolution Infrared Spectrograph). We present overviews of
the technical capabilities of each of these instruments and show how those capabilities
translate into meeting key TMT science requirements. Finally, we provide an update on the
design progress of these three instruments.
13096-32
18 June 2024 • 10:50 - 11:10 Japan Standard Time
Show Abstract +
We present the status of HISPEC and MODHIS, the next-generation infrared spectrographs for Keck and the Thirty Meter Telescope. By offering single-shot, R=100,000 spectroscopy between 0.98 - 2.46 μm, both instruments will enable spectroscopy of transiting and non-transiting exoplanets in close orbits, direct high-contrast detection and spectroscopy of spatially separated substellar companions, and exoplanet dynamical mass and orbit measurements using precision radial velocity monitoring calibrated with a suite of state-of-the-art absolute and relative wavelength references. Both Keck-HISPEC and TMT-MODHIS use an innovative architecture taking advantage of powerful adaptive optics facilities at Keck and TMT. The compact, diffraction-limited spectrographs are fed by single-mode fibers. HISPEC is currently in full-scale development, with a first light at Keck Observatory slated in 2026. MODHIS is currently in conceptual development phase but benefits from the synergistic parallel development of HISPEC.
13096-33
Science instruments for the Giant Magellan Telescope
(Invited Paper)
18 June 2024 • 11:10 - 11:40 Japan Standard Time
Show Abstract +
We describe the development status of the first generation of science instruments for the Giant Magellan Telescope (GMT) and the very broad range of first-light capabilities that they will deliver. G-CLEF, a visible light echelle designed for broad scientific use and for precision radial velocity measurements, is in fabrication. The other instruments are all in preliminary design: GMACS, a high throughput (into the UV) medium-wide field multi-object spectrograph; GMTNIRS, a near- to thermal-infrared echelle spectrograph utilizing silicon immersion gratings to achieve a very compact design capable of unprecedented spectral grasp in a single exposure; GMTIFS, a diffraction limited near-infrared imager and integral field spectrograph; and the Ex-AO system GMagAO-X for very high contrast imaging and spectroscopy (e.g. by feeding the high spectral resolution spectrographs G-CLEF and GMTNIRS) of extrasolar planets. The first-generation suite also includes a robotic fiber-feed system called MANIFEST, currently in conceptual design, that enables spectroscopy over the full 20 arcmin field of view of the telescope and can feed any of the spectrographs.
13096-34
18 June 2024 • 11:40 - 12:00 Japan Standard Time
Show Abstract +
We present the preliminary design of GMagAO-X, the first-light high-contrast imager planned for the Giant Magellan Telescope. GMagAO-X will realize the revolutionary increase in spatial resolution and sensitivity provided by the 25 m GMT. It will enable, for the first time, the spectroscopic characterization of nearby potentially habitable terrestrial exoplanets orbiting late-type stars. Additional science cases include: measurement of young giant exoplanet variability; characterization of stellar atmospheres at high spectral resolution; and mapping of resolved objects. These will be enabled by a 21,000 actuator extreme adaptive optics system, a coronagraphic wavefront control system, and a suite of imagers and spectrographs. We will review the science-driven performance requirements for GMagAO-X. We will provide an overview of the resulting mechanical, optical, and software designs optimized to deliver this performance. We will present an overview of our end-to-end performance modeling and simulations. Finally, we will review the results of Preliminary Design Review held in February, 2024, and present the project plan to have GMagAO-X ready at first-light of the GMT.
Break
Lunch Break 12:00 - 13:20
Session 9:
Instruments for Extremely Large Telescopes II
18 June 2024 • 13:20 - 15:40 Japan Standard Time
Session Chair:
Ruben Sanchez-Janssen, UK Astronomy Technology Ctr. (United Kingdom)
13096-35
18 June 2024 • 13:20 - 13:40 Japan Standard Time
Show Abstract +
The discovery of a fair sample of Earth-analogues (Earth 2.0’s), i.e. rocky, Earth-mass exoplanets orbiting a Solar-type star in that host star’s habitable zone, and a subsequent search of evidence of bioactivity on those Earth 2.0’s by the detection of biogenically produced molecules in those exoplanetary atmospheres, are two of the most urgent observational programs in astrophysics and science in general. To identify an Earth 2.0, it is necessary to measure the reflex motion radial velocity amplitude of the host star at the 10 cm/sec level, a precision considerably below that which is currently achievable with existing instruments. The follow-on project to search for the biomarkers in an Earth 2.0’s atmosphere may require an effective planet/star contrast of 10-10, again well below the currently achievable level. In this paper, we discuss technical innovations in the implementation of the GMT-Consortium Large Earth Finder (G-CLEF) spectrograph that will enable these observational objectives. We discuss plans to operate G-CLEF at the Magellan Clay telescope with the MagAO-X adaptive optics system and subsequently with GMagAO-X at the Giant Magellan Telescope (GMT).
13096-36
18 June 2024 • 13:40 - 14:00 Japan Standard Time
Show Abstract +
MANIFEST is a fibre-fed positioning system poised to redefine astronomical exploration through its advanced capabilities for the 24.5m Giant Magellan Telescope (GMT). With a 14 arcmin field of view, MANIFEST facilitates groundbreaking key research in Galactic Archealogy, dynamical masses of dwarf galaxies, galaxy stellar kinematics, and the exploration of the reionisation epoch through Lyman alpha observations. Its unique features include high multiplexing, deployable integral field units (IFUs), increased spectral resolution, and the potential for simultaneous observations with multiple instruments, enabling a comprehensive understanding of celestial phenomena. For the first light, MANIFEST will use the GMT's current planned first light instruments: G-CLEF (an echelle resolution spectrograph) and GMACS (low/mid resolution spectrograph). MANIFEST will connect with these existing optical spectrographs and offer various multiplexing and IFU modes. MANIFEST stands as a pivotal tool for unlocking the mysteries of the universe, offering unparalleled opportunities for transformative discoveries in modern astrophysics.
13096-37
18 June 2024 • 14:00 - 14:20 Japan Standard Time
Show Abstract +
MICADO will enable the ELT to perform diffraction limited near-infrared observations at first light. The
instrument’s capabilities focus on imaging (including astrometric and high contrast) as well as single object
slit spectroscopy. It will achieve an unprecedented combination of sensitivity and resolution at near-infrared wavelengths using its own SCAO system as well as the LGS-MCAO module MORFEO (formerly know as MAORY). This contribution will provide an overview about the final design of the instrument, its current manufacturing status and timeline. Some lessons learned from the final design review process will be presented related to the challenges arising from the substantial differences between projects for the VLT and the ELT.
Finally, MICADO's expected performance will be discussed, with a special emphasis on MICADO's relation and complementarity to the JWST.
13096-38
18 June 2024 • 14:20 - 14:40 Japan Standard Time
Show Abstract +
The Mid-Infrared ELT Imager and Spectrograph (METIS) will be one of only three 1st generation science instruments on the 39m Extremely Large Telescope (ELT). METIS will provide diffraction-limited imaging and medium resolution slit-spectroscopy from 3 – 13 microns (L, M, and N bands), as well as high resolution (R ~100,000) integral field spectroscopy from 2.9 – 5.3 microns. Both imaging and IFU spectroscopy can be combined with coronagraphic techniques.
After the final design reviews of the optics (2021) and the entire system (2022), the hardware procurements have started. In this paper we present the final design of METIS and provide an overview of the various ongoing activities. Many hardware components are already in hand, and the manufacturing is in full swing in order to start the assembly and testing of the subsystems in 2024. We also discuss the complex assembly and test phase of the system, for which a dedicated facility is currently being prepared. First light at the telescope is expected in 2028.
13096-39
18 June 2024 • 14:40 - 15:00 Japan Standard Time
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ANDES, the ArmazoNes high Dispersion Echelle Spectrograph, will be the high-resolution spectrograph of the European ELT at optical and near-infrared wavelengths and is being developed thanks to the efforts of a a large, internation consortium composed of more than 220 scientists and engineers from 33 institutes in 13 countries.
ANDES ia a fibre-fed spectrograph providing a spectral resolution of 100,000 with a simultaneous wl range of 0.4-1.8 µm, with the goal of extending it to 0.35-2.4 µm with the addition of the U and K bands. It will operate in seeing- and diffraction- limited conditions, including a unique SCAO+IFU module in the 1.0-1.8 µm range.
ANDES science cases span nearly all areas of research in astrophysics and even fundamental physics. Top science cases include the detection of biosignatures from exoplanet atmospheres, the signatures of the first generation of stars (PopIII), tests on the stability of Nature's fundamental couplings, and the direct detection of the cosmic acceleration.
I will provide a general overview of the ANDES project, its main science cases, its status following the System Architecture Review and the forthcoming steps to construction.
13096-40
18 June 2024 • 15:00 - 15:20 Japan Standard Time
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HARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 450nm to 2450nm with resolving powers from 3500 to 18000 and spatial sampling from 60mas to 4mas. It can operate in two Adaptive Optics modes - SCAO (including a High Contrast capability) and LTAO - or with NOAO. The project is preparing for Final Design Reviews.
HARMONI is a work-horse instrument that provides efficient, spatially resolved spectroscopy of extended objects or crowded fields of view. The gigantic leap in sensitivity and spatial resolution that HARMONI at the ELT will enable promises to transform the landscape in observational astrophysics in the coming decade.
The project has undergone some key changes to the leadership and management structure over the last two years. We present the salient elements of the project restructuring, and modifications to the technical specifications. The instrument design is very mature in the lead up to the final design review. In this talk, we provide an overview of the instrument's capabilities, its component systems and sub-systems, and its operational concept.
13096-41
18 June 2024 • 15:20 - 15:40 Japan Standard Time
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MOSAIC is the Multi-Object Spectrograph (MOS) for the 39m Extremely Large Telescope (ELT) of the European Southern Observatory (ESO), with unique capabilities in terms of multiplex, wavelength coverage and spectral resolution. It is a versatile multi-object spectrograph working in both the Visible and NIR domains, designed to cover the largest possible area (~40 arcmin²) on the focal plane, and optimized to achieve the best possible signal-to-noise ratio on the faintest sources, from our Galaxy to the epoch of the reionization.
In this paper we describe the main characteristics of the instrument, including its expected performance in the different modes. The status of the project will be briefly presented, together with the positioning of the instrument in the landscape of the ESO instrumentation. We also review the main expected scientific contributions of MOSAIC, focusing on the synergies between this instrument and other major ground-based and space facilities.
Break
Coffee Break 15:40 - 16:10
Session 10:
Solar Instruments
18 June 2024 • 16:10 - 17:20 Japan Standard Time
Session Chair:
Marc F. Kassis, W. M. Keck Observatory (United States)
13096-42
DKIST instrumentation system commissioning
(Invited Paper)
18 June 2024 • 16:10 - 16:40 Japan Standard Time
Show Abstract +
The Daniel K. Inouye Solar Telescope, with its 4m aperture, is the largest telescope for observations of the Sun, and is currently in its Operations Commissioning Phase. During this phase of the project, the five DKIST first light instruments, the Visible Broadband Imager (VBI), the Visible Spectro-Polarimeter (ViSP), the Diffraction-Limited Near-Infrared Spectro-Polarimeter (DL-NIRSP), the Cryogenic Near-Infrared Spectro-Polarimeter (Cryo-NIRSP) and the Visible Tunable Filter (VTF) are used in selected modes to acquire scientific data. We provide an overview of the DKIST instrumentation system and its inherent flexibility. We further report on lessons learned during commissioning, and present sample data products.
13096-43
18 June 2024 • 16:40 - 17:00 Japan Standard Time
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The Visible Tunable Filter Instrument (VTF) is a 2D imaging spectropolarimeter for high spatial and spectral resolution solar observations in the visible light. It is based on two large Fabry-Pérot etalons (FPI’s) as spectral filters.
The field of view of 1 arcmin combined with a spectral accuracy below 1 picometer leads to a clear aperture (CA) of 250 mm, an allowed cavity error smaller than 3 nm RMS over the CA, a microroughness below 1 nm and a required cavity stability of +/- 100 pm over one hour. Therefore, the world’s largest tunable etalons for imaging applications had to be built. We describe the overall design and specifications of the VTF-FPI’s and discuss the challenging tasks that had to be solved to realize this unique instrument. We present the main characteristics of the first etalon as measured in the laboratory and demonstrate the dynamic response probed by the integrated metrology system.
13096-44
18 June 2024 • 17:00 - 17:20 Japan Standard Time
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We advocate for the development of a ground-based network of robotic instruments provisionally called ngGONG to maintain critical observing capabilities for synoptic research in solar physics and for the operational space weather forecast. ngGONG will consist of 6 geographically-distributed stations, with longitudes and weather patterns selected to provide nearly continuous observations of the Sun. ngGONG instruments will include: spectropolarimeters for precise measurements of vector magnetic fields at multiple heights in the solar atmosphere; an instrument for line-of-sight Doppler velocity measurements required for studies of the solar interior and farside; rapid narrow-band images; sun-as-a-star instruments; and tunable Ha imager and limited coronagraph capabilities to monitor the violent ejecta of magnetized plasma from the Sun’s atmosphere and determine coronal magnetic topologies and plasma properties. We will discuss the requirements for such an observing system, and present its conceptual design.
Wednesday Plenary Session
19 June 2024 • 08:30 - 10:00 Japan Standard Time
Join us for the Wednesday morning plenary talks.
Break
Coffee Break 10:00 - 10:20
Session 11:
AO Instrument I
19 June 2024 • 10:20 - 12:00 Japan Standard Time
Session Chair:
Marc F. Kassis, W. M. Keck Observatory (United States)
Show Abstract +
SCALES (the Slicer Combined with an Array of Lenslets for Exoplanet Spectroscopy) is the next generation, diffraction-limited, thermal infrared, fully cryogenic coronagraphic exoplanet imager and lenslet-based integral field spectrograph for W.M. Keck Observatory. The imager mode operates from 1 to 5 microns with selectable narrow- and broadband filters, and the spectrograph operates from 2 to 5 microns with both low and mid spectral resolutions (R~100 to R~7500). The SCALES consortium includes UC Observatories and the UC campuses, W.M. Keck Observatory, the Indian Institute of Astrophysics, and the University of Durham, with over 40 science team members. We report on the overall design and project status during its ongoing fabrication phase, which started in early 2023.
13096-46
19 June 2024 • 10:40 - 11:00 Japan Standard Time
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ULTIMATE-Subaru is the next-generation facility instrument program of the Subaru Telescope which will extend the existing Subaru’s wide-field survey capability to the near-infrared (NIR) wavelength. The ULTIMATE-Subaru instrument suite includes Ground-Layer Adaptive Optics (GLAO) and wide-field near-infrared instruments, aiming to provide ~ 0.2 arcsec image size at K band (2.2 micron) over 20 arcmin diameter field of view at the Cassegrain focus. The planned first-light instrument is a Wide-Field Imager (WFI), which covers a 14 x 14 square arcmin field of view in NIR wavelength. The instrument development is led by Subaru/NAOJ in collaboration with ANU, Tohoku University, ASIAA, and the University of Tokyo. The GLAO and WFI are currently in the final and the preliminary design phases, respectively, aiming to conduct the commissioning at the telescope in 2028. In this presentation, an overview of the ULTIMATE-SUBARU instruments, their current status, and future prospects will be presented.
Show Abstract +
MAVIS is the world’s first facility-grade visible MCAO instrument, currently under development for the VLT. The AO system will feed an imager and an integral field spectrograph, with 50% sky coverage at the Galactic pole. MAVIS has unique angular resolution and sensitivity at visible wavelengths, and is highly complementary to both JWST and ELTs. We describe both instruments in detail and the broad range of science cases enabled by them. The imager will be diffraction-limited in V, with 7.36 mas per pixel covering a 30” FOV. A set of at least 5 broad-band, 3 medium-band and 16 narrow-band filters will provide imaging from u to z. The spectrograph uses an advanced image slicer with a selectable spatial sampling of 25 or 50 mas to provide integral field spectroscopy over a FOV of 2.5”x3.6”, or 5”x7.2”. The spectrograph has two identical arms each covering half the FOV. Four interchangeable grisms allow spectroscopy with R=4,000 to R=15,000, from 370-935 nm.
13096-48
19 June 2024 • 11:20 - 11:40 Japan Standard Time
Show Abstract +
The National Astronomical Research Institute of Thailand, together with the Institut d'Optique Graduate School and Centre de Recherche Astrophysique de Lyon, has been developing the Evanescent Wave Coronagraph (EvWaCo) - a new kind of Lyot coronagraph that uses a lens and prism placed in contact as its focal plane mask. Based on the principle of frustrated total internal reflection, EvWaCo enables an achromatic rejection and the ability to collect the light from the star and the companion. An EvWaCo prototype equipped with adaptive optics will be installed at the Thai National Telescope as an on-sky demonstrator. This demonstrator will work on a 1.2 m x 0.8 m elliptical sub-aperture of the Thai National Telescope to reach a raw contrast of 10^{-4} at 3 λ/D over the wavelength range [600 nm, 900 nm]. The completed optical design contains all the essential light path channels in high contrast imaging fitted inside a 960 mm x 960 mm optical breadboard, namely the guiding camera channel, companion channel, star channel, and wavefront sensing channel. We also present the results of the tolerancing and straylight analysis.
13096-49
19 June 2024 • 11:40 - 12:00 Japan Standard Time
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The ORCAS Keck Instrument Demonstrator (ORKID) is a visible-light diffraction-limited camera that was installed behind the WMKO Keck II AO system in the fall of 2022. Its primary purpose is to act as a pathfinder instrument for adaptive optics-fed visible-light imaging at Keck with current and future planned upgrades. ORKID is diffraction-limited down to 650nm and can operate with millisecond frame rates, enabling frame selection and frame registration in post-processing. Here we provide an overview of the commissioning of the instrument and describe its on-sky performance. Using Keck’s Shack-Hartmann and pyramid wavefront sensors, we are able to achieve images with point-spread function cores of 15-17 milliarcseconds FWHM with and without frame registration, respectively. We report on PSF quality as a function of frame selection fraction and guide star brightness. Finally, we provide a gallery of scientific objects of interest observed so far with ORKID.
Break
Lunch Break 12:00 - 13:20
Session 12:
High-dispersion Spectrographs II
19 June 2024 • 13:20 - 15:30 Japan Standard Time
Session Chair:
Livia Origlia, INAF - Osservatorio di Astrofisica e Scienza dello Spazio (Italy)
13096-50
Performance characterization of the iLocater spectrograph
(Invited Paper)
19 June 2024 • 13:20 - 13:50 Japan Standard Time
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iLocater is a new, near-infrared, extreme precision radial velocity (EPRV) spectrograph under construction for the dual 8.4m diameter Large Binocular Telescope (LBT). The instrument uses single-mode fibers (SMFs) injected with adaptive optics for illumination. We present the integration process for the spectrograph and cryostat systems, and the laboratory performance testing that has been completed. Testing has included optical performance characterization at ambient and cryogenic temperatures, assessment of cryogenic thermal control of the system (80-100K) at sub-mK level, and instrument detector performance (an H4RG-10). The optimized spectrograph and cryostat system will be delivered to the LBT in 2024.
13096-51
19 June 2024 • 13:50 - 14:10 Japan Standard Time
Show Abstract +
Of late adaptive optics coupled compact spectrometers have been much discussed in the literature as an inexpensive means to obtaining very high resolving power (R ~ 100,000 or higher) spectroscopy on large telescopes. The Palomar Radial Velocity Instrument (PARVI), fitting in shoebox-sized space, is the first such instrument on sky and is designed to carry out JH band radial velocity measurements while coupled via single mode fiber transport to an extreme AO system, as well as an electro-optic modulation generated laser frequency comb. In this presentation we discuss the instrument, its current performance, and describe some of the special challenges involved in achieving robust operation at the diffraction limit.
13096-52
19 June 2024 • 14:10 - 14:30 Japan Standard Time
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Diffraction-limited spectrographs are key instruments for upcoming large telescopes thanks to their compact sizes that do not scale with telescope diameter and their stable point spread functions that are conducive to precise radial velocity (RV) measurements of exoplanets. A challenge to achieving sub meter-per-second RVs with diffraction-limited spectrographs is what we refer to as "differential limb coupling", which is the preferential coupling of one limb of a star over the other due to an imperfect centering of a partially resolved star on a fiber. The RV error is exacerbated when the star is faster rotating and more resolved by an optical system. It can become significant when coupling to single-mode fibers due to their sensitivity to source position on the fiber. In this paper we quantify the RV error induced by differential limb coupling and estimate that for 1 mas RMS pointing errors, the RV error term for a star 0.1 mas in diameter rotating at 2 km/s would be 0.5 m/s for Keck-HISPEC and 4 m/s for TMT-MODHIS. We present several design strategies we expect would reduce this RV error term including that adopted by HISPEC, which is currently in its detailed design phase.
13096-53
19 June 2024 • 14:30 - 14:50 Japan Standard Time
Show Abstract +
MARVEL is a new state-of-the-art facility at the Mercator Observatory (La Palma, Spain) targeting high precision radial velocity measurements. The facility consists of an array of four 80-cm telescopes feeding a single stabilised high-resolution echelle spectrograph. It will provide essential ground-based RV follow-up on transit measurements by previous and upcoming space missions with an RV precision of 1m/s. This precision requires simultaneous wavelength calibration monitoring on a reliable wavelength reference calibration source. In this contribution, we describe the MARVEL wavelength calibration system and the strategy that will be deployed to maximize calibration precision and long-term stability.
13096-54
19 June 2024 • 14:50 - 15:10 Japan Standard Time
Show Abstract +
RISTRETTO is a visible high-resolution spectrograph fed by an extreme adaptive optics (AO) system, to be proposed as a visitor instrument on ESO VLT. The main science goal of RISTRETTO is to pioneer the detection and atmospheric characterisation of exoplanets in reflected light, in particular the temperate rocky planet Proxima b. RISTRETTO will be able to measure albedos and detect atmospheric features in a number of exoplanets orbiting nearby stars for the first time. It will do so by combining a high-contrast AO system working at the diffraction limit of the telescope to a high-resolution spectrograph, via a 7-spaxel integral-field unit (IFU) feeding single-mode fibers. The project is in the manufacturing phase for the spectrograph sub-system, and the preliminary design phase for the AO front-end. RISTRETTO is a pathfinder instrument in view of similar developments at the ELT, in particular the SCAO-IFU mode of ELT-ANDES and the future ELT-PCS instrument.
13096-55
19 June 2024 • 15:10 - 15:30 Japan Standard Time
Show Abstract +
Precise and accurate wavelength calibration of spectrographs is essential for key science cases, e.g. the search for extrasolar planets, a possible variation of fundamental constants and the direct observation of cosmic expansion.
A crucial tool for this are laser frequency combs (LFCs), directly linking the accuracy of atomic clocks to optical laser lines.
However, strong material dispersion and large spectral separation from the established infrared laser oscillators so far prevent the use of LFCs for spectrograph calibration in the blue and UV part of the spectrum. At OHP/SOPHIE, we demonstrated for the first time the calibration of an astronomical spectrograph using an astrocomb in the ultraviolet spectral range below 400nm. Key technology used were nano-fabricated, periodically-poled waveguides in lithium niobate photonic chips, fed by either a robust infrared electro-optic comb generator or a chip-integrated microresonator comb. In an end-to-end test, we could demonstrate stable and accurate LFC-based spectrograph calibration, showcasing a viable path towards precision wavelength calibration of spectrographs in the ultraviolet, crucial e.g. for the future ELT/ANDES.
Break
Coffee Break 15:30 - 16:00
Session 13:
Instruments with New Concept/Technologies II
19 June 2024 • 16:00 - 17:20 Japan Standard Time
Session Chair:
Armando Gil de Paz, Univ. Complutense de Madrid (Spain)
13096-56
19 June 2024 • 16:00 - 16:20 Japan Standard Time
Show Abstract +
An ultra-compact optical spectrograph (~43x16x13cm) is developed using a new optical arrayed waveguide technique based on waveguide spectral lenses (WSL). The WSL is an evolved version from the arrayed waveguide grating design can achieve simultaneous spectral dispersion and image focusing onto the detector plane at designed distance. Despite its compact size, the instrument maintains high optical throughput and provides a wide range of spectral resolution (R~200-2000 at 600-950 nm). The spectrograph's design and the results of laboratory testing will be reported.
13096-57
19 June 2024 • 16:20 - 16:40 Japan Standard Time
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We report on the progress of Henrietta, a new near-infrared low-resolution (R ~ 200) spectrograph for the 1-meter Swope telescope at Las Campanas Observatory in Chile. With a bandpass from 600 - 2400 nm, Henrietta is designed to perform transmission spectroscopy of exoplanet atmospheres around bright stars and routinely reach the photon noise limit. Henrietta's design choices that enable routine, high-precision observations are its wide 25 x 3 arcminute field of view, its wide 15-20 arcsecond slit, and its beam-shaping diffuser that broadens the point spread function out to hundreds of pixels. Henrietta is currently at Carnegie Observatories, where it is undergoing optical assembly and alignment, as well as spectrophotometric testing to identify Henrietta's spectrophotometric noise floor. Upon finishing assembly and testing in Summer 2024, Henrietta will be shipped to Las Campanas Observatory where it will begin commissioning and subsequently observe tens of exoplanet atmospheres a year.
13096-58
19 June 2024 • 16:40 - 17:00 Japan Standard Time
Show Abstract +
The PLACID instrument is a novel high-contrast direct imaging facility that was recently delivered to the Turkish 4-m DAG telescope, with first light anticipated later this year. The project passed the Delivery Readiness Review (DRR) milestone in May 2023, and was delivered to the DAG operator ATASAM earlier this year. Once on-sky, PLACID will be the world’s first “active coronagraph” facility, fielding a customized spatial light modulator (SLM) acting as a dynamically programmable focal-plane phase mask (FPM) coronagraph from H- to Ks-band. We hereby present the delivered PLACID instrument, its current capabilities, and on-site commissioning results.
13096-59
19 June 2024 • 17:00 - 17:20 Japan Standard Time
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We have undertaken the development of novel high-efficiency and wide spectral coverage grisms for MOIRCS, the near-infrared imager and multi-object spectrograph at the Subaru Telescope. While our prior medium-resolution gratings, incorporating Volume Phase Holographic (VPH) gratings, exhibited remarkable efficiency, their narrow transmission curves posed limitations on scientific applications. As part of the enhancement initiative for the existing VPH gratings, we successfully developed new high-sensitivity and wide-spectral-coverage grisms (“LightSmyth grisms”) tailored for the J & H window in 2019, utilizing their novel transmission gratings. Following this achievement, we initiated the development of a comparable medium-dispersion grism for the K-band (“VB-K grism”), incorporating our proprietary Volume-Binary (VB) Grating. The fabrication of the VB-K grism was completed by summer 2023, and we are presently awaiting on-sky performance evaluation which is scheduled for early 2024.
Thursday Plenary Session
20 June 2024 • 08:30 - 10:00 Japan Standard Time
Join us for the Thursday morning plenary talks.
Break
Coffee Break 10:00 - 10:20
Session 14:
Wide Field Imager
20 June 2024 • 10:20 - 12:10 Japan Standard Time
Session Chair:
Armando Gil de Paz, Univ. Complutense de Madrid (Spain)
13096-60
Completion of the LSST camera integration
(Invited Paper)
20 June 2024 • 10:20 - 10:50 Japan Standard Time
Show Abstract +
The LSST Camera assembly is a complex, highly integrated instrument for the Vera C. Rubin Observatory. Now that the assembly is complete, we present the highlights of the LSST Camera assembly; successful installation of all Raft Tower Modules (RTM) into the cryostat, integration of the world’s largest lens with the camera body, and successful integration and testing of the shutter and filter exchange systems. While the integration of the LSST Camera is a story of success, there were challenges faced along the way; component failures, implementing late design changes, and challenges with facility infrastructure.
13096-61
20 June 2024 • 10:50 - 11:10 Japan Standard Time
Show Abstract +
The Keck Wide Field Imager (KWFI) is a 1-degree field of view imager optimized to take advantage of the UV performance of the W.M. Keck Observatory (WMKO) located atop Mauna Kea in Hawaii. KWFI is an all-fused silica 4-lens element corrector that operates over u,g,r,i, and z photometric bands from 300 – 1000 nm where the design achieves 0.5” 80% encircled energy diameter rms over the FOV within each photometric band. In 2022 we reported on the conceptual design of the imager. More recently, the Keck Science Steering Committee has directed the team to advance the development of a Deployable Secondary Mirror (DM2) which will work in conjunction with KWFI. The DM2 is a 1.4-meter lightweight hexagonal secondary mirror that is remotely deployable to allow fast switching between KWFI and any Cassegrain or Nasmyth Instruments. We report here on the conceptual design of DM2 and the progress on the imager design.
13096-62
20 June 2024 • 11:10 - 11:30 Japan Standard Time
Show Abstract +
JPCam, a 1.2 Gpixel camera deployed on the 2.6m, large field-of-view JST250 telescope, has started to take the data from the J-PAS, a photometric survey of several thousand square degrees of the northern sky in 59 optical bands, 54 of them narrow-band filters (145Å FWHM), contiguous and equi-spaced between 370 and 920nm, producing a low resolution photo-spectrum of every pixel of the observed sky, hence promising crucial breakthroughs in Cosmology and galaxy formation and evolution. JPCam is equipped with a mosaic of 14 9.2k x 9.2k, 10µm pixel, low noise detectors from T-e2V, providing a FoV of 4.1 square degrees with a plate scale of 0.2267′′/pix. Camera electronics allows read times of 10.9s with a readout noise of 5.4e in full frame mode. To fully optimize image quality, position of JST250 secondary mirror and JPCam itself are maintained optically aligned by means of two hexapod systems. JPCam has started scientific operation and the first J-PAS data is becoming available, as well as first scientific results. JPCam on sky performances and first science results are presented in this paper.
13096-63
20 June 2024 • 11:30 - 11:50 Japan Standard Time
Show Abstract +
Large field-of-view rapid sky surveys are important approaches of time-domain astronomy research. The "Antarctic Time Domain Astronomical Optical Observational Array" called the Antarctic Tianmu Plan consists of an array of dozens of small wide-field optical telescope systems covering a 10000 square degree sky area. A prototype of the Antarctic Tianmu Program was developed in 2020-2022 and shipped to the Zhongshan Station in Antarctica at the end of 2022. This paper mainly reports the quality of images and limiting magnitudes, observational results, and long-term stability of the system operation during the first year of observation.
13096-90
20 June 2024 • 11:50 - 12:10 Japan Standard Time
Show Abstract +
The LSST Camera is the sole instrument for the Vera C. Rubin Observatory, it consists of a 3.2 gigapixel focal plane mosaic with in-vacuum controllers, dedicated guider and wavefront CCDs, a three-element corrector whose largest lens is 1.55 meters in diameter, six optical interference filters covering a 320-1050nm bandpass with an out-of-plane filter exchange mechanism, and camera slow control and data acquisition systems capable of digitizing each image in 2 seconds. In this paper, we describe the verification testing program performed throughout the Camera integration and results from characterization of the Camera’s performance. These include an electro-optical testing program, measurement of the focal plane height and optical alignment, and integrated functional testing of the Camera’s major mechanisms: shutter, filter exchange system and refrigeration systems. The Camera is due to be shipped to the Rubin Observatory in 2024, and plans for its commissioning on Cerro Pachon will be briefly described.
Break
Lunch Break 12:10 - 13:30
Session 15:
Wide-band Spectrographs
20 June 2024 • 13:30 - 14:30 Japan Standard Time
Session Chair:
Kentaro Motohara, National Astronomical Observatory of Japan (Japan)
13096-65
20 June 2024 • 13:30 - 13:50 Japan Standard Time
Show Abstract +
SOXS (Son Of X-Shooter) is the new ESO instrument for the 3.58-m New Technology Telescope at the La Silla Observatory. It is going to provide the fundamental spectroscopic counterparts to the ongoing and upcoming imaging surveys, becoming one of the premier transient follow-up instruments in the Southern hemisphere. SOXS is a single object spectrograph offering a wide simultaneous spectral coverage from U- to H-band. The NTT+SOXS system is specialized to observe all transients and variable sources discovered by imaging surveys with a highly flexible schedule maintained by the consortium, based on a heavy usage of Target of Opportunity observations. It is going to be highly synergic with the upcoming transients discovery machines like the Vera C. Rubin Observatory and others.The instrument has been integrated and tested in Italy, collecting and assembling subsystems coming from all partners spread over six countries in three continents. Some preparatory activities in Chile have been completed at the telescope. This article gives an updated status of the project before the shipping of the instrument to Chile.
13096-66
20 June 2024 • 13:50 - 14:10 Japan Standard Time
Show Abstract +
The Muztage-Ata One-point-nine-three-meter Synergy Telescope (MOST) is a novel equatorial telescope currently being constructed in China. Spectroscopy of bi-Channel with UlTra-wide band and high flUx for MOST (SCUTUM) serves as one of the first-light instruments and it adopts a modified FOSC type design with two channels. The instrument converts F/8 beam from the telescope to a nearly F/4.3 beam. The spectroscopy of SCUTUM can be performed in the wavelength range 310-1000nm in one exposure, offering various choices of grisms and slits with resolution ranging from 250 to 7500. To optimize total throughput, SCUTUM employs high-efficiency optical elements, coatings, and sensitivity-enhanced detectors. The overall transmission from the collimator to the detector is anticipated to exceed 20% at 330nm and surpass 45% at wavelengths above 355nm when operating in R<3000 mode. The designed weight of this instrument amounts to approximately 280kg. The instrument is currently planned to be assembled in the Institute laboratory and to be commissioned on MOST by late 2024. This paper presents the design methodology, techniques employed, and expected optical performance.
13096-67
20 June 2024 • 14:10 - 14:30 Japan Standard Time
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ProtoPol is a medium-resolution echelle spectro-polarimeter initially conceived as the prototype instrument of currently under development M-FOSC-EP (Mt. Abu Faint Object Spectrograph and Camera-Echelle Polarimeter) instrument – a two-channel multimode instrument which is currently being designed for PRL 1.2m and 2.5m telescopes at Mt. Abu. ProtoPol was conceived to evaluate the development methodology of M-FOSC-EP with commercially available off-the-shelf components. Similar to M-FOSC-EP, the ProtoPol was designed on the concept of echelle and cross-disperser gratings to record the cross-dispersed spectra in the wavelength range from 390 to 940 nm but with lower resolution (R~7000-8000). ProtoPol has been fully assembled and integrated and is currently being characterized in the laboratory for its performance and other parameters. It is expected to see the first light on the telescope in November-December 2023. The design and development methodology of ProtoPol with complete off-the-shelf components offers a cost-effective way to develop spectro-polarimeters with such resolutions for small aperture (2-3m) telescopes around the world with a short development period.
Session 16:
AO Instrument II
20 June 2024 • 14:30 - 15:30 Japan Standard Time
Session Chair:
Kentaro Motohara, National Astronomical Observatory of Japan (Japan)
13096-68
20 June 2024 • 14:30 - 14:50 Japan Standard Time
Show Abstract +
SHARK-NIR is an instrument providing high-contrast coronagraphic imaging, dual band imaging and low resolution spectroscopy in the near infrared, taking advantage of the high performance of the Large Binocular Telescope (LBT) AO systems in synergy with SHARK-VIS and LMIRCam to detect and characterize exoplanetary systems. Shipped and installed at LBT between June and November 2022, SHARK-NIR was the subject of four successful commissioning runs between January and October 2023, after which our first early scientific run in October 2023 focused on the Taurus constellation, a region populated by targets of considerable scientific interest. We give an overview of commissioning and the early science phases running from October 2023 to May 2024, focusing on the technical challenges we overcame and future work needed to push the instrument to its very limit, as well as presenting the first preliminary scientific results.
13096-69
20 June 2024 • 14:50 - 15:10 Japan Standard Time
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The Keck Planet Imager and Characterizer (KPIC), a series of upgrades to the Keck II Adaptive Optics System and Instrument Suite, aims to demonstrate high-resolution spectroscopy of faint exoplanets that are spatially resolved from their host stars. In this paper, we measure KPIC’s sensitivity to companions as a function of separation (i.e., contrast curve) using on-sky data collected over the last three years. KPIC is able to achieve on-sky sensitivity to planets that would be within the inner working angle of state-of-the-art coronagraphic instruments. We decompose the KPIC performance budget into individual noise terms and discuss limiting factors. We identify sources of systematic noise that were not anticipated and discuss mitigation efforts for both KPIC and for similar instruments.
13096-70
20 June 2024 • 15:10 - 15:30 Japan Standard Time
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FRIDA is a diffraction-limited imager and integral-field spectrograph for the adaptive-optics focus of the Gran Telescopio Canarias. In imaging mode FRIDA provides scales of 10, 20 and 40 mas/pixel and in IFS mode spectral resolutions of about 1200, 4000 and 30,000. Coronographic masks are available in both modes for high-contrast images. At the time of writing, FRIDA is completely integrated, with the exception of the detector, and is starting system testing in the laboratory. The detector is due to be integrated early in 2024 and we expect to deliver the instrument to the telescope at the end of 2024. In this contribution we present a summary of FRIDA's design, fabrication, current status and potential scientific applications.
Break
Coffee Break 15:30 - 16:00
Session 17:
IFS II
20 June 2024 • 16:00 - 17:30 Japan Standard Time
Session Chair:
Ruben Sanchez-Janssen, UK Astronomy Technology Ctr. (United Kingdom)
13096-71
20 June 2024 • 16:00 - 16:30 Japan Standard Time
Show Abstract +
The Sloan Digital Sky Survey V (SDSS-V) is a panoptic survey designed to investigate a wide range of forefront problems in astrophysics. SDSS-V is organized into three mappers, including the Local Volume Mapper (LVM). LVM will map thousands of square degrees of sky, delivering tens of millions of spectra to depths of about 1 Rayleigh. To achieve our ambitious goals, the Local Volume Mapper Instrument (LVM-i) is designed to execute this survey from Las Campanas Observatory in Chile. In this Proceeding, we describe the system-level performance, the construction, and the commissioning of the Local Volume Mapper Instrument. The architecture of the system is designed to reach the faintest depths, and we describe LVM-i's main building blocks: the enclosure and building, the four 16.1-cm-diameter telescopes that deliver sharp images from 360 nm - 980 nm, the integral-field fiber system with 1,950 fibers, and three high-grasp spectrographs with FWHM resolution of 75 km/s at Ha, as well as our software system.
13096-72
20 June 2024 • 16:30 - 16:50 Japan Standard Time
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TARSIS (Tetra-Armed Super-Ifu Spectrograph) is a wide-field IFU with an 8-arcmin^2 FoV that has been already adopted by the Calar Alto Observatory (CAHA) for its 3.5m telescope and is currently under preliminary design phase. The TARSIS image-slicer fills the instrument FoV completely and, combined with the TARSIS four spectrographs, yields a spectral resolution of R~1000 in the range between 320-520nm (three spectrographs/quadrants) and 510-810nm (one spectrograph/quadrant) with a spaxel size of 2x2 arcsec^2. The scientific objective of TARSIS is to carry out the CATARSIS survey, a blind-spectroscopic mapping of 16 galaxy clusters in the range 0.15< z<0.28 up to their virial radii that will make use of all available dark time at the CAHA 3.5m for six years. CATARSIS will start as soon as TARSIS is available at the telescope, which is estimated for 2028.
13096-73
20 June 2024 • 16:50 - 17:10 Japan Standard Time
Show Abstract +
Narrowband integral field spectrographs (NB-IFS)—capable of obtaining simultaneous, moderate to high-resolution spectra over a wide and continuous field of view, and within a constrained pass-band—represent a relatively new class of UV-visible astronomical instrumentation. With its exquisite low surface brightness sensitivity, the NB-IFS is optimal for velocity-resolved, emission-line mapping of a wide range of extended astrophysical phenomena. We have recently deployed CHaS, the Circumgalactic H-alpha Spectrograph on the MDM 2.4m Hiltner telescope on Kitt Peak, AZ, and are currently developing new NB-IFS concepts for ground- and space-based applications. We present here a generalized framework for designing, optimizing and assessing the optomechanical designs of NB-IFS over a broad range of scales, architectures, and capabilities. We also present a suite of novel architectures that highlight the differing ways that astrophotonics, metasurfaces, proposed detector technologies and image processing techniques will continue to advance NB-IFS capabilities over the coming decade.
13096-74
20 June 2024 • 17:10 - 17:30 Japan Standard Time
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BlueMUSE is a blue-optimised, medium spectral resolution, panoramic integral field spectrograph under development for the Very Large Telescope (VLT). With an optimised transmission down to 350 nm, spectral resolution of R~3500 on average across the wavelength range, and a large FoV (1 arcmin2), BlueMUSE will open up a new range of galactic and extragalactic science cases facilitated by its specific capabilities. The BlueMUSE consortium includes 9 institutes located in 7 countries and is led by the Centre de Recherche Astrophysique de Lyon (CRAL). The BlueMUSE project development is currently in Phase A, with an expected first light at the VLT in 2031. We introduce here the Top Level Requirements (TLRs) derived from the main science cases, and then present an overview of the BlueMUSE system and its subsystems fulfilling these TLRs. We specifically emphasise the tradeoffs that are made and the key distinctions compared to the MUSE instrument, upon which the system architecture is built.
Session PS1:
Posters - Performance and Results from Recently Commissioned Instruments
17 June 2024 • 17:30 - 19:00 Japan Standard Time
13096-75
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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4MOST, a versatile spectroscopic facility, is being prepared for installation on the ESO VISTA Telescope at Paranal. Comprehensive laboratory testing of the instrument is underway to ensure it meets technical specifications and key user requirements. This phase involves characterizing the performance of its 3 spectrographs and calibration unit, focusing on spectral performance, system stability, and fiber throughput. These aspects are critical for achieving 4MOST's ambitious science goals. The testing also includes a selection of user requirements to confirm the instrument's readiness for various scientific objectives. Results from these tests are pivotal in shaping the observational strategy for future operations. This paper details the preparatory work, testing procedures, and expected impact of these tests on the final verification at the telescope, commissioning, and normal science operations. This initial testing phase is a crucial step in the 4MOST project, laying the groundwork for successful commissioning.
13096-77
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the deployed calibration system of CRIRES+, the premiere high-resolution, cross-dispersed near-infrared (0.9-5.4um) spectrograph in operation at the ESO/VLT. We discuss the first two years of operation of its spectral and spatial calibration system, as well as the robustness and reliability in the field, and its maintenance and resulting lessons learnt.
Among the suite of wavelength calibrators is a newly developed, unique infra-red Fabry-Perot etalon (FPI), complementing gas-absorption cells for precision radial velocimetry and atomic emission line sources. The stabilized FPI simultaneously covers the Y-K bands and provides an unprecedented frequency comb of homogeneous, high-contrast spectral features, dramatically enhancing instrument calibration and monitoring. We highlight the technology developments required for stabilized infra-red FPIs, present the FPI performance in routine operations within the CRIRES+ instrument and its wavelength calibration fidelity, and demonstrate how the FPI has proven a versatile tool for characterization.
13096-78
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Dark Energy Spectroscopic Instrument (DESI) represents a groundbreaking development in the field of observational astronomy due to both the scale and efficiency of the instrument.One of its critical components, the DESI fiber system, is designed to facilitate the efficient capture of spectra from a multitude of celestial objects. This paper summarizes the on-sky performance evaluation of the DESI fiber system, focusing on its key characteristics and capabilities. The stability of the fiber system, a crucial aspect for survey integrity, is assessed under different observing conditions.
13096-79
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Diffraction-Limited Near Infrared Spectropolarimeter (DL-NIRSP) is a facility instrument of the NSF's Daniel K. Inouye Solar Telescope (DKIST). DL-NIRSP was originally commissioned with two birefringent fiber optic Integral Field Units (IFUs) for high resolution observations on the solar disk and wide field, high sensitivity measurements above the limb in the solar corona. These IFUs support contiguous 2D-spatial, spectral, and polarimetric measurements in three channels between 500 and 1800 nm with very high spectral resolution over narrow bandpasses. During commissioning, we found temporal variations of a flat field and other fiber-related issues limited instrument performance. To resolve these various problems, we replaced the fiber-based IFUs with the high resolution Machined Imager Slicer IFU with 36 micron wide slitlets (MISI-36). We report on the implementation and optical testing of MISI-36.
13096-80
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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After almost 6 years of routine operations at the GTC, EMIR has recently been upgraded with a new Hawaii2RG infrared detector which has replaced the old Hawaii2. In this contribution, we will describe the capabilities of the new EMIR and will show some fresh scientific results, that are compared with similar observations taken with the old detector.
13096-81
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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GHOST is a newly operational optical fibre-fed high-resolution spectrograph at the Gemini South 8.1m telescope. It currently offers the choice of two resolution modes captured by slicing one (or two) input IFUs with a FOV of 1.2" and a spectral resolving power of 56,000 and 76,000 for the unbinned CCDs. At the high-resolution mode, one can also instigate a simultaneous ThXe calibration lamp, which along with a simultaneous pseudo-slit profile constructed from reformatting the input IFU image will allow for precision radial velocity measurements. Here we talk about the proposed roadmap towards full queue operation, potential upgrades, and the error terms contributing to the final on-sky RV precision, which is estimated to be in the 1-10m/s range.
13096-82
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We report the commissioning progress and on-sky performance of two new integral field units (IFUs) for the Gemini Near-Infrared Spectrograph (GNIRS). The commissioning of these modes opens up new scientific opportunities for spatially resolved spectroscopy on Gemini. The IFUs were designed and built at the Centre for Advanced Instrumentation in Durham University, as part of Gemini’s Instrument Upgrade Program. The Low Resolution IFU (LR-IFU) has a field-of-view of 3.15" x 4.80" sampled with a pixel scale of 0.15”It currently covers the X,J,H, and K bands with a spectral resolution of R~1700−7200 depending on the grating. The High Resolution IFU (HR-IFU) has a 1.80" x 1.25" field-of-view at a 0.05” sampling, and is optimized for fully adaptively corrected images delivered by the Gemini North ALTAIR AO system.
13096-83
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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IGRINS-2 is a near-infrared spectrograph for the Gemini Observatory, which obtains cross-dispersed H- and K-band spectra simultaneously with a spectral resolution R=45,000, developed by Korea Astronomy and Space Science Institute (KASI). The electronics system for the spectrograph was designed based on its predecessor, IGRINS (Immersion GRating INfrared Spectrograph), with several changes, including components to control field devices and detectors. For detector controls, three H2RG infrared FPAs acquire images for science spectra and a slit-view camera, and three MACIEs, SIDECAR cryoboards, and detector control computers control the FPAs. Field devices include components for temperature control, pressure monitoring, a calibration unit, and a power supply unit. The instrument control computer controls the field devices within a private Ethernet network for the spectrograph. We present the design of the entire electronics system and the characterization results for detectors.
13096-84
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The InfraRed Doppler (IRD) spectrograph can provide high-resolution (R > 70,000) spectra over 1000-1700 nm with stable wavelength calibrations thanks to a dedicated laser frequency comb. Since the first science operation on the Subaru 8.2-m Telescope in 2018, IRD has been extensively used for observations, in which the main field is exoplanet but some studies cover the fields of Galaxy evolution and compact object. One of the main outputs is the discovery of a super-Earth close to the habitable zone of cool M dwarf Ross 508. IRD was also used to constrain the masses of many planets identified with TESS, and to identify the atomic/molecular features of transiting planets. Recently, the extreme adaptive optics system, SCExAO, can be combined with IRD to directly characterize a substellar companion with high-contrast and high-resolution spectroscopy. We here highlight and summarize the outputs obtained via the six-year operation of IRD.
13096-85
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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IRD-SSP is an ongoing exoplanet survey using InfraRed Doppler (IRD) on the Subaru Telescope. One of the main goals of this survey is to search for Earth-mass planets in the habitable zones of M dwarfs. The major noise source that limits the stability of the near-infrared radial velocity (RV) measurements is the Earth’s atmospheric contamination in a spectrum, which can introduce false RV signals. Our study examines this issue in the RV pipeline for the IRD-SSP. We assessed the impact of telluric lines on RV stability by comparing observed and theoretical models and testing with mock spectra. We found that despite small discrepancies between observed and model telluric, those residuals can cause RV variations of 1-2 m/s and limit the stability of RV measurements in the near-infrared.
13096-86
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Keck Planet Imager and Characterizer (KPIC) is a series of upgrades for the Keck II Adaptive Optics system and the NIRSPEC spectrograph to enable diffraction-limited, high-resolution (R>30,000) spectroscopy. KPIC’s use of single-mode fibers provides a substantial reduction in sky background and a stable line-spread function. In this paper we present the recent upgrades expanding science capabilities to y-H bands, adding laser frequency combs, and enhancing the vortex fiber nulling mode. We show results from preliminary on-sky tests in the first few months of re-commissioning, along with the next steps for the instrument.
13096-87
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Keck Planet Imager and Characterizer (KPIC) combines high contrast imaging with high resolution spectroscopy (R~35,000 in K band) to study directly imaged exoplanets and brown dwarfs in unprecedented detail. KPIC aims to spectrally characterize substellar companions through measurements of planetary radial velocities, spins, and atmospheric composition. To measure reliable exoplanet properties, systematic noise can be mitigated through modeling in post processing or directly by modifying hardware. Currently, the dominant source of systematic noise for KPIC is fringing, or oscillations in the spectrum as a function of wavelength. In KPIC, the fringing signal is due to three transmissive optics acting as Fabry Perot cavities and can dominate residuals by up to 10% of the continuum for high SNR exposures. We explore two mitigation strategies: forward modeling the fringing with a physically informed model of Fabry Perot cavities and wedging two of the transmissive optics.
13096-88
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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LOFAR is currently the largest radio telescope operating at the lowest frequencies that can be observed from earth. It is a distributed telescope with a dense core of stations located in the north of the Netherlands combined with international stations across Europe, creating a telescope the size of Western Europe. LOFAR is currently being upgraded to LOFAR2.0. We present an overview of the validation of the new timing distribution system, showing the improvements in timing stability for the upgraded LOFAR2.0.
13096-89
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The world's largest low-frequency (10-250MHz) radio telescope -- the pan-European Low-Frequency Array (LOFAR) -- is undergoing an upgrade of its hardware, firmware and software to improve its unique observing capabilities targeting a variety of scientific use cases, ranging from galaxy evolution, transients and cosmic rays to space weather and lightning research.
The LOFAR2.0 upgrade will increase the sensitivity of the telescope by doubling the number of digitized antennas operating in the 10-90 MHz frequency range, and allowing simultaneous observing with the antennas observing between 110 and 250 MHz.
We present the stepwise validation of the LOFAR2.0 system elements based on their performance on a variety of quantities. Early integration ensures a smooth transition from validating a single receiver to the full-scale station with almost three hundred receivers.
The upgraded stations, combined with the upgraded clock distribution, network, central processor and telescope manager, will be delivered in subsequent array releases to validate the LOFAR2.0 telescope incrementally and ensure smooth transition to operations.
13096-91
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Here, we present the method and results of the lab Acceptance, Testing and Integration of the spectrograph system for the Local Volume Mapper (LVM) instrument. LVM has recently been commissioned and is designed to conduct a vast spectroscopic survey in the optical and near IR (360 - 980 nm with spectral resolution R ~ 4000) of thousands of square degrees of sky from Las Campanas, Chile. The LVM instrument consists of four 16 cm telescopes which feed three spectrographs through 1944 fibers from a lenslet-coupled fiber IFU. The spectrographs were tested at Carnegie Observatories in Pasadena, CA by the use of a test setup which simulates the light input to the fiber IFU. This setup consists of various remotely switchable continuum and spectral line light sources to illuminate the spectrograph through a test fiber cable and test fiber slit. Using this, the spectrograph was tested on various metrics such as focus and image quality, optical thermal stability, detector characteristics and throughput and the results of those tests are documented here.
13096-92
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
MOONS is the Multi-Object Optical and Near-infrared Spectrograph for the ESO Very Large Telescope (VLT). MOONS will be able to simultaneously observe ~1000 targets using individual robotic theta-phi positioners. The instrument will provide both medium and high-resolution spectral coverage across the wavelength range of 0.65 μm to 1.8 μm.
In this paper we will describe the integration and testing of the fully-assembled Rotating Front End of MOONS. This incorporates the fibre positioning module, the front-end structure and the metrology, calibration and acquisition sub-systems. There will also be a discussion of system control and associated hazard analyses and safety cases. The as-built performance of the completed system will be demonstrated, including metrology-verified fibre positioning accuracy, reconfiguration efficiency, and flat-field fibre calibration performance. Finally, a summary of the successful installation of the field corrector assembly at VLT UT1 will be presented.
13096-93
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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MOONS is a Multi-Object Optical and Near-infrared Spectrograph currently under testing as a third-generation instrument for the Very Large Telescope (VLT).The Infrared detectors used on MOONS are contained within a large, 4mx2.5mx2.5m cryostat with a 4 Tonne cold mass. Pumpdown of the chamber to 2x10-5mbar is achieved within 24 hours using two Pfeiffer 2000l/s turbo pumps. Initial Cooldown of the instrument uses a gravity fed LN2 Precool System with level sensors to automatically control the LN2 flow. When the cryostat reaches it’s assigned operating temperature an active cooling system takes over to maintain the steady-state temperature. Integration and engineering tests have been carried out to assess the performance of the Cryostat and Control System. This poster presents an overview of the system, results from integration and thermal testing of the system, along with unforeseen issues and how these challenges were resolved.
13096-94
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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In this paper we report on the discovery, through on-sky and in-lab measurements and hardware inspection, and repair of the erroneous mounting of the PFS VPHG gratings. Analysis of the performance loss based on Koegelnik's coupled wave theory and empirical fitting to component-level measurements is presented, and the recovered performance is shown. Guidelines for future instrument designers will be proposed, in order to minimize the risk of such flaws happening again.
13096-95
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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PFS (Prime Focus Spectrograph) is an ultra-wide-field, multi-object spectrograph currently being commissioned at Subaru telescope. The focal plane is made of ∼2400 science fibers and fiber positioners at the telescope prime focus, covering a field of view of 1.3 deg in diameter. The science fibers will be connected to 4 identical spectrograph modules, each receiving ∼600 fibers. Every spectrograph module will host 3 cameras, covering the blue (380-650 nm), red (630-970 nm) and near-infrared (940-1260 nm) wavelengths.
This presentation will focus on the completion of the PFS spectrograph modules at the Subaru telescope. We will present their integration and test processes and measured performance, as well as the technical challenges encountered along the way, and the solutions used to correct them.
13096-96
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Subaru Prime Focus Spectrograph (PFS) will soon be the first massively-multiplexed wide-field spectrograph on a 8-meter class telescope. PFS’s spectrograph system covers the optical to near-infrared—380 to 1260nm—in a single exposure and is fed by 2386 reconfigurable fibers distributed across a 1.3-degree wide field of view. Leveraging deep multiband imaging catalogs, particularly from Subaru’s Hyper Suprime-Cam (HSC) imager, PFS will fuel future discoveries in cosmology, galaxy evolution, and galactic archaeology. To fully leverage Subaru’s 8.2 meter aperture and probe the faintest targets, accurate spectral reduction and sky subtraction are critical to PFS’s operation. In commissioning of the PFS, the accuracy of the sky subtraction algorithms is being assessed through direct observations of the night sky. Here, we report the current status of the sky-subtraction routines, as determined from the commissioning data.
13096-97
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
After subsystems of the PFS were delivered to the Subaru telescope, several engineering runs were carried out to test the functions and system performance. Through the process, several improvements and calibrations were made especially on the acquisition and guiding cameras. With the data accumulated from the engineering runs, the possible factors that determine the successful rate of the Cobra positioner movements of the PFS has been analyzed with the goal to improve the overall efficiency of the target convergence. These analyses helped improving the performance of the Cobra positioners as well as optimizing the number of the iterations to reach the targets. Details of the analysis and the performance improvement for the target convergence will be reported.
13096-98
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the optical performance verification results for the Prime Focus Spectrograph (PFS), fiber optics module, so-called “CableBs” at Subaru Telescope. CableB employs $2386$ fibers and delivers light from the fiber positioning module to the spectrographs.
After completing the installation of all four CableBs at the telescope in June 2023, we verified four areas of optical performance; continuity, uniformity, throughput, and focal ratio degradation (FRD). Each verification showed comparable results with measurements undertaken at the integration site. We therefore conclude that the CableB installation at Subaru telescope was successful.
13096-99
17 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The Spectrograph System of Subaru Prime Focus Spectrograph (PFS) is fed by 2400 fibers and consists of four identical spectrograph modules with 4 arms and 600 fibers each. This paper recalls the overall integration process for the spectrograph module series, presents the test procedures and results for the Spectrograph System, the anomalies and issues we overcame in the series, and finally the delivery and installation of four modules at the Subaru Telescope in Hawai`I in 2019, 2022 and 2023. We detail the strategies developed to resolve technical issue such as defocus and tilt encountered after the delivery of the first module for the visible focal planes. We extensively present the optical and thermal performance of the spectrograph system. Finally, we present and discuss lessons learned for the largest 8m-class multi-object spectrograph system.
13096-100
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We describe improvements made to the existing polarimetric calibrations of the Southern African Large Telescope to correct for an unexpected time-dependent position angle ``ripple'' vs wavelength which has been seen in high-precision RSS observations and appears to be due to variations in the pupil illumination during an observation. The new calibration technique explicitly models the pupil dependence of the polarimetric sensitivity. The net spectral polarization sensitivity vs field of view position (X; Y) and wavelength are computed as the polarization pupil dependence, weighted by the pupil intensity illumination of the observation. For the polarization pupil dependence, degree P and position angle are well represented by a polynomial function of position in the pupil. A pupil intensity illumination model has been devised and calibrated by using twilight observations. The polarization pupil dependence model has been calibrated using observations of the full Moon. The final calibration has been checked using repeated observations of known highly polarized standard stars.
13096-101
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Three fiber integral field units (IFU) are being built in the SAAO fiber-lab for the Robert Stobie Spectrograph's visible arm and the future red arm. The 200 micron fibre IFU has 309 x 0.9 arcsec diameter spatial elements covering an elongated hexagonal footprint of 414 sq. arcsec is currently being commissioned. Each IFU sits in its own slit-mask cassette and is referred to as a slit-mask IFU (SMI). These are inserted in the same fashion as the existing long-slit cassettes at the SALT focal plane. Prismatic fold mirrors direct the focal plane into the fiber IFU and then back into the RSS collimator after the fibres are routed 180 deg within the cassette and formatted into a pseudo-slit. In this paper we update on the laboratory characterization and on-sky commissioning-performance of Slit Mask IFU.
13096-102
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The SOAR Telescope Echelle Spectrograph (STELES) is a second-generation instrument to be installed at the 4.1m SOAR telescope, adding high-resolution and near UV spectroscopic capabilities to the available instrumentation of the telescope. STELES is a Nasmyth fed, double-channel (blue and red), grating (volume phase holographic (VPH)) cross-dispersed echelle spectrograph. Both channels will operate in quasi-Littrow mode and in white pupil configuration. Using two independent sets of slit masks, the instrument will observe both the object and the nearby sky spectrum, simultaneously covering the 300-900 nm spectral range with spectral resolving power of R~50,000. The bench spectrograph will be permanently mounted on the telescope for stability and easy access (below the Nasmyth platform) and fed by fore-optics installed in the Optical ISB port. In this work, we describe the instrument development and the efforts for its installation on the telescope in November 2023. We also present the first engineering and on-sky results, together with the alignment procedure of the optical components and stability tests in the laboratory and at the telescope.
13096-104
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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This paper presents the opto-mechanical integration and alignment, functional and optical performance verification of the NIR arm of SOXS instrument.
SOXS will be a single object spectroscopic facility for the ESO-NTT 3.6-m telescope, made by two arms high efficiency spectrographs, able to cover the spectral range 350-2000 nm with a mean resolving power R≈4500. In particular the NIR arm is a cryogenic echelle cross dispersed spectrograph spanning the 780-2000 nm range.
We describe the integration and alignment method performed to assemble the different opto-mechanical elements and their installation on the NIR vacuum vessel, which mostly relies on mechanical characterization. The tests done to assess the image quality, linear dispersion and orders trace in laboratory conditions are summarized. The full optical performance verification, namely echellogram format, image quality and resulting spectral resolving power in the whole NIR arm (optical path and science detector) is detailed. Such verification is one of the most relevant prerequisites for the subsequent full instrument assembly and provisional acceptance in Europe milestone, foreseen in 2024.
13096-105
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The SOXS spectrograph is designed for the ESO NTT telescope, operating in both the optical and NIR bands through two arms: the UV-VIS (350-850 nm) and the NIR (800-2000 nm). This article presents an overview of the final tests conducted on the UV-VIS camera system using the telescope simulator. It details the system's performance evaluation and highlights the advancements in the upgraded version of the acquisition system.
The UV-VIS detector system integrates a setup comprising the e2v CCD 44-82 and a custom detector head linked with the ESO Continuous Flowing Cryostat (CFC) cooling system, managed by the New General Detector Controller (NGC) developed by ESO.
The telescope simulator, located in the Padua laboratory, incorporates a mechanical derotator and emulates the electronic environment, including racks, harnessing, and power supply, mirroring the final configuration anticipated for installation on the ESO-NTT telescope.
This paper specifically outlines the current status of the UV-VIS camera and presents conclusive results from the detector system performance within the telescope simulator, offering insights into its preparedness before integration onto the ESO-NTT telescope
13096-106
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Son Of X-Shooter (SOXS) is a single object spectrograph, built by an international consortium for the 3.58-m ESO New Technology Telescope at the La Silla Observatory. It offers a simultaneous spectral coverage over 350-2000 nm, with two separate spectrographs. In this paper we present the conclusion of the AIT phase of the Near InfraRed (NIR) cryogenic echelle cross-dispersed spectrograph, that is currently under PAE in the premises of the INAF - Astronomical Observatory of Padova (It).
13096-107
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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SOXS (Son Of X-Shooter) is the new single object spectrograph for the ESO New Technology Telescope (NTT) at the La Silla Observatory, able to cover simultaneously both the UV-VIS and NIR bands (350-2000 nm).
The instrument is currently in the integration and test phase, approaching the Preliminary Acceptance in Europe (PAE) before shipment to Chile for commissioning.
After the assembly and preliminary test of the control electronics at INAF - Astronomical Observatory of Capodimonte (Napoli), the two main control cabinets of SOXS are now hosted in Padova, connected to the real hardware.
This contribution describes the integration strategy chosen for the SOXS control electronics, the tests that have been performed and an overview of the experiences gained during the different phases of the project.
13096-108
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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SPIRou (SpectroPolarimètre Infra-Rouge in French), is a near-infrared, fiber-fed spectropolarimeter at the Canada-France-Hawaii Telescope (CFHT) which gives full spectral coverage from 0.98 to 2.35 μm with a resolving power of 70,000. To obtain an RV precision of ~1 m/s, SPIRou must measure and average the redshift of as many spectral lines as possible. The K-band contains many such lines making K-band sensitivity very important. Unfortunately, the original thermal background suppression design did not work as expected so that the background is over 5 times higher than desired reducing the K-band sensitivity by 2-3 magnitudes. Some of the background has been eliminated by cooling the fiber interface at the entrance to the spectrograph, but the fiber injection unit on the telescope still produces a large amount of background and is more difficult to cool. This paper will describe the cooling system installed on the fiber injection unit and its performance.
13096-109
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Transneptunian Automated Occultation Survey (TAOS II) camera is designed to cover the 1.7 degree diameter field of view of the 1.3m telescope with 10 mosaic 4.5K × 2K e2v CIS 113 CMOS sensors. The CIS 113 has a back illumination thinned structure to provide similar performance to that of the back-illumination thinned CCDs. Star boxes with size of 8 × 8 pixels can be read at 20Hz with a pixel rate of 1M pixel/sec per channel. The on site performance with the telescopes for both full frame images and window mode lightcurves as well as the synchronization of the three cameras will be presented.
13096-110
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the upgrades to the visible light (600 nm - 800 nm) high-contrast imaging polarimeter SCExAO/VAMPIRES on the 8.2 m Subaru telescope. The upgrades included new photon-counting CMOS detectors with 0.2 e- RMS read noise, a novel multiband imaging mode, an achromatic liquid crystal for fast polarization modulation, all controlled with a modern asynchronous Python framework. We highlight the observational capabilities of VAMPIRES including: H-alpha imaging, coronagraphy, multiband color analysis, spectral differential imaging, and simultaneous multi-instrument polarimetry with SCExAO. We conclude with the on-sky validation and first-light results, important considerations for observers, and future prospects with VAMPIRES.
13096-111
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Visible Aperture Masking Polarimetric Imager for Resolving Exoplanetary Structures (VAMPIRES) is a visible light instrument on the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system. The components of the system – M3, half-wave plate, image rotator, and FLC – have unknown and for some time-varying diattenuations and retardances. To characterize the instrumental polarization of the system, measurements with a polarized internal calibration source were taken to provide diattenuation and retardance estimates of components downstream of the telescope mirrors. Using MCMC techniques, we developed detailed Mueller matrix models for two versions of VAMPIRES, before and after its 2023 upgrade. Observations of unpolarized standard stars were used to estimate M3’s diattenuation. Polarized standard stars were observed to estimate M3’s retardance and quantify the models’ accuracies. Model Mueller matrices from measurements are compared to expected theoretical matrices derived from polarimetric ray tracing and are applied in preliminary data analysis stages to polarimetric imaging disk targets.
13096-112
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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WINERED is a PI-type near-infrared (z, Y, J-bands) high dispersion spectrograph developed by Koyama Astronomical Observatory of Kyoto Sangyo University and the University of Tokyo (Ikeda et al. 2022). In 2022, WINERED was moved to the 6.5-m Magellan II - Clay telescope at Las Campanas Observatory (LCO) to take advantage of its extremely high sensitivity (the instrumental total throughput ~60%), which is its best feature, and started scientific observations in 2023. This paper presents the details of the development undertaken for the relocation, the instrumental performance when attached to the Magellan telescope, and its operational structure and strategy.
13096-113
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Dutch Rubin Enhanced Atmospheric Monitor – DREAM – brings high-resolution, real-time information on all-sky transparency and cloud coverage to the Vera C. Rubin Observatory. Leveraging the MASCARA legacy, DREAM employs five wide-field cameras, pointing upward and in the four cardinal directions. It precisely measures the brightness of all bright stars (V < 8.4) with a cadence of 6.4 seconds. These data are used to provide the actual cloud cover at an approximate cadence of 30 seconds. Additionally, DREAM produces calibrated light curves for stars brighter than magnitude 8.4, extending the temporal coverage of the MASCARA southern hemisphere survey. Integrated and tested at Leiden Observatory in 2023, DREAM was shipped in November of the same year and installed in close proximity to the Vera C. Rubin Observatory. In its initial phase, DREAM supplies cloud coverage and transparency data to the Auxiliary Telescope. Once the main camera of the Vera C. Rubin Observatory becomes operational, DREAM will play a crucial role in optimizing the survey strategy by providing input to the scheduler, particularly in non-photometric conditions.
13096-114
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The QUIJOTE (Q-U-I JOint TEnerife) Experiment led by the IAC, has designed the new MFI2 instrument that aims to characterise the polarised emission of the CMB, as well as Galactic and extra-Galactic sources. This instrument is expected to be 2–3 times more sensitive than the former MFI and has five polarimeters, working in the microwave band of 10-20GHz.
It is composed of a cylindrical cryostat cooled by a closed helium cycle cryocooler with two stages. The opto-mechanical system consists of five horns aligned with the focal plane of the telescope where the signal enters the instrument, each horn is followed by the FEM cooled down to less than 20K. This signal leaves the instrument to be processed at the BEM.
It is described the mechanical/ thermal design, manufacture, integration and commissioning of the MFI2 instrument, as well as tests of the opto-mechanical elements, cryostat cooling/vacuum system and measurements of the scientific commissioning.
13096-115
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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MORISOT (MOnet Robotic Instrument for Spectroscopy Of Transients) is a low resolution spectrograph covering the optical wavelength range. Its compact and basic design, mainly consisting of commercial components, reduces both costs and maintenance effort. MORISOT is installed at our 1.2m robotic MONET/S telescope located at SAAO.
Our newly designed frontend at the telescope will enable the commissioning of MORISOT. With this frontend, MORISOT is able to run fully robotically. Moreover, a second 25 cm telescope can be used to simultaneously operate photometric observations of the same objects.
The fully robotic operations are handled by pyobs, which runs our robotic telescopes for photometric observations and has been extended regarding the handling of guiding, spectroscopy and photometry at once. Since the beginning of 2024, the first use case is a high cadence survey of changing look AGN, while also transitting exoplanets are investigated.
13096-116
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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OPASpec is a double spectrograph covering 360-900 nm with a spectral resolution of R ~2000 on a single detector. The blue channel (360-565 nm) and red channel (565-900 nm) combined to cover this broad optical bandpass tailored to our observational goals for the Original PolyOculus Array (OPA). A dichroic splits incident light so that blue/red light are reflected/transmitted to its respective channel’s optical path. Each channel contains two separate collimating lenses, VPH transmission gratings, and an assortment of custom lenses fabricated by Optimax. The two channels share the same focal plane detector, an Atik APX60 CMOS camera. We present the design, fabrication, calibration, and commissioning processes of OPASpec and report initial astronomical observations taken with the instrument.
13096-117
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Polarimetric observations can provide important information on many astronomical phenomena beyond that available via conventional imaging and spectroscopy alone, such as the characterization of astrophysical magnetic fields. We present here an overview of the Gemini GPOL+NIRI instrument commissioning project, which aims to bring an IR imaging polarimetry visiting instrument capability to NOIRLab’s Gemini North telescope. We discuss the GPOL hardware unit itself, how it works in concert with Gemini facility instruments (particularly NIRI), and the current details and status of the refurbishment and commissioning project. We also discuss future plans for polarimetric instrument modes at Gemini North, including GPOL+GNIRS NIR spectropolarimetry and the advent of GPI 2.0.
13096-118
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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In 2024, the NIRC2 infrared camera at the Keck II 10-m telescope will undergo an upgrade that will enable a suite of new polarimetric observing modes in observing bands J to L’ including coronagraphic imaging, standard imaging, and spectropolarimetry. The upgrade includes a pair of half-wave plates which have been characterized at wavelengths between 1.4 μm and 2 μm. The transmission of each waveplate was measured directly and the retardance was found from the Mueller matrix by using a dual-rotating retarder polarimeter setup. In addition, an anti-reflective nano-texture coating was tested on a waveplate without creating a noticeable change in the retardance.
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We report on two critical upgrades to NIRC2, the workhorse diffraction-limited infrared instrument in use with the Keck II telescope Adaptive Optics (AO) system at the W. M. Keck Observatory. NIRC2 has been in operation for over two decades and it is one of the most productive instruments at WMKO. The NIRC2 detector is a 1Kx1K InSb Aladdin-3. We have upgraded the detector electronics from the original system based on transputers to a state-of-the-art Archon controller. One of the most demanded NIRC2 observing modes is high-contrast imaging using Vector Vortex Coronagraphic (VVC) masks, which have been available to the NIRC2 observing community since 2015. To maximize the attenuation of the AO-generated Point Spread Function (PSF) core, the star needs to be precisely centered on the vortex mask over the course of an observation. This is achieved with a servo loop control software based on the Quadrant Analysis of Coronagraphic Images for Tip-tilt Sensing (QACITS) technique. We have migrated the original IDL-based QACITS software to Python, including several updates and a new graphical interface. Both Archon and QACITS upgrades are aimed at boosting the NIRC2 observing efficiency.
13096-121
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We describe the installation of significant upgrades to the SNIFS CALibration Apparatus (SCALA), which feeds NIST-traceable optical light into the University of Hawaii 2.2m telescope on Maunakea, and then on to the SuperNova Integral Field Spectrograph (SNIFS), for the purposes of transfering the NIST calibration to standard stars. The upgrades include new, high-sensitive picoammeters calibrated relative to two NIST photodiodes, significantly improved baffling, enhanced rejection of monochromator out-of-band light, a chopper to better correct for daytime scattered light in the telescope dome, a new fiber bundle, and recoating of mirrors. We have also upgraded the optics in our calibration lights source to reduce scattered light, thermoreflectance and polarization, enabling even better calibration transfer from the NIST photodiodes to our picoammeters. We are now in the process of obtaining standard star observations with SCALA calibration, thereby laying the groundwork for a NIST-traceable calibration of these standard stars.
13096-122
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Submillimeter Array (SMA) is an array of 8 antennas operating at millimeter and submillimeter frequencies on Mauna Kea, Hawaii, operated by the Smithsonian Astrophysical Observatory and Academia Sinica, Taiwan. Over the past several years, we have been preparing a major upgrade to the SMA that will replace the aging original receiver cryostats and receiver cartridges with all new cryostats and new 230 and 345 GHz receiver designs. This wideband upgrade (wSMA) will also include significantly increased instantaneous bandwidth, improved sensitivity, and greater capabilities for dual frequency observations. In this paper, we will describe the wSMA receiver upgrade and status, and first on-sky testing results from the prototype wSMA receiver, as well as the future upgrades that will be enabled by the deployment of the wSMA receivers.
13096-123
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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RoboPol is a four-channel and one-shot linear optical polarimeter. It is successfully operating since 2013 on the Skinakas Observatory's 1.3 m telescope in Crete, Greece. Using it's unique optical system, it measures the linear Stokes parameters q and u in a single exposure with a high polarimetric accuracy of 0.1 % and 1 deg in polarization angle in R broadband filter. It performs marginally worse in other broadband filters. The source of the current instrumental performance limit is unaccounted and variable instrumental polarization due to factors such as temperature and gravity induced instrument flexure.
To improve the performance of RoboPol, we have developed a rotating half-wave plate calibrator system. This calibrator system is placed at the beginning of the instrument and enables modulation of polarimetric measurements by beam swapping between all the four channels.
With this calibrator system, we have observed on four nights across two annual observing seasons of RoboPol. We have attained a polarimetric accuracy better than 0.05 % and 0.5 deg in polarization angle for all the filters, improving the instrument performance by a factor of 2.
13096-124
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The new VLBI data acquisition system (OCTAVE-DAS) have been developed for VLBI Exploration of Radio Astrometry (VERA) and the East Asia VLBI Network (EAVN) based on the VSI-H and VDIF specifications at the National Astronomical Observatory of Japan. It consists of 1) a high speed 1-20 Gsps 3-10 bit RF(-30 GHz) direct sampler with DBBC functions, 2) media converter between one 10 GigE port and four 2 Gbps input and output ports conformable to VSI-H, 3) new VLBI recorders have functions of both recording and playing at a maximum rate of 32 Gbps and 4) Gbit real-time correlator and software correlator system using GPGPU technology. These OCTAVE-DAS instruments are connected via 10 GigE network with VDIF and VSI specifications. These components have been used for VERA, Japanese VLBI Network (JVN) and EAVN. We will report on current status and results of scientific broad-band (16 Gbps) VLBI test observation using the OCTAVE-DAS.
13096-126
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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WEAVE is a powerful multi-object spectrograph constructed by an international collaboration for the 4.2-m William Herschel Telescope, at the Roque de Muchachos Observatory on La Palma in the Canary Islands. In its main MOS observing mode, up to 1000 WEAVE optical fibres can be positioned in the 2-deg-diameter focal plane, each gathering the light from an individual target.
While a 1-hour observation is in progress with this configuration of fibres, a second set of 1000 fibres can be configured, and the two sets are swapped at the end of the observation.
In this way, nearly all of the night can be used for observing in MOS mode.
The spectrograph can be used in low-resolution mode, R ~ 5000, or high-resolution mode, R ~ 20000. Additional fibre-bundles can be deployed for integral-field spectrosopy.
WEAVE will be used to carry out a series of high-impact surveys complementing other ground-based (e.g. LOFAR) and space (e.g. GAIA facilities).
In this paper, we report on the commissioning of the instrument and its
sub-systems: the new prime-focus corrector providing the WHT with a 2-deg field of view, the fibre-positioner [the subject of a separate abstract], the fibre systems (MOS and integral-field modes), the acquisition and guiding cameras, the spectrograph, the detectors, and the software and protocols which allow observing-block management, queue-scheduling, instrument-control, data reduction and archiving.
13096-127
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We discuss the design, prototyping, fabrication, integration, verification, and commissioning of the DDRAGO wide-field multi-channel imager for the 1.3 meter COLIBRÍ telescope for the Observatorio Astronómico Nacional in Mexico. The instrument has blue and red channels which have fields of 26 arcmin. It also delivers a faster infrared beam to the CAGIRE imager which has a field of 22 arcmin. The instrument is designed to provide initial follow-up of GRBs detected by the ECLAIRs instrument on the SVOM satellite, but will also support a much wider program of observations of transient and multi-messenger sources. DDRAGO is a descendent of the successful RATIR imager, but the optical design is significantly more complex to allow much wider fields.
13096-128
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The programmable Liquid-crystal Active Coronagraphic Imager for the DAG Telescope (PLACID) instrument is expected to be on-sky by the end of 2024. PLACID will be the first “active stellar coronagraph”, equipped with a customized spatial light modulator (SLM) , which performs as a dynamically programmable focal-plane phase mask (FPM). Our python based numerical simulator of SLM-based focal-plane phase coronagraphy focuses on the effect of discrete pixelated FPM patterns in place of classical phase mask. In general, the tool enables the detailed simulation of PLACID or similar SLM-based instruments, and can help with real-time operations and interpretation of real data. Additionally, the tool is designed to evolve to integrate and simulate advanced operation modes, in particular focal-plane phase diversity for coherent differential imaging (CDI) of exoplanets. We present the current status of our code, early simulations, a first comparison with PLACID commissioning results and lessons learned.
13096-129
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The world’s first “adaptive stellar coronagraph” facility will be the PLACID instrument, installed on Turkey's new national observatory 4-m DAG telescope. PLACID incorporates a customized spatial light modulator (SLM) acting as a dynamically addressable focal-plane phase mask (FPM) coronagraph in the H – Ks bands. This new approach to high-contrast imaging will be tested on-sky in late 2024.
We present a first estimate of the science discovery space for PLACID, in terms of exoplanet and disk targets, considering foreseen adaptive optics performance, contrast, limiting magnitudes, coronagraphic inner working angle, etc. We also look into predicted disk and binary/multiple star systems imaging performance, with the latter being a possible niche science case for the instrument (adaptive FPM for multiple stars). This work will inform on the first light PLACID commissioning activities with ATASAM (Atatürk University) and is conceived to enable the Turkish or external astronomers to plan future observations.
13096-130
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We are developing an imager with high throughput at near-ultraviolet wavelengths (300-400 nm; around the u-band) for a ground-based telescope. The optical design and detector selection are optimized for this wavelength range at the expense of the efficiency at longer wavelengths, so that we expect a peak efficiency of 20 percent including sky transmission and telescope optics at u-band. The imager is currently in construction and will be deployed for the first on-sky observation in early 2024 at the 1.5-m Kanata Telescope at Higashi-Hiroshima Observatory. We will also incorporate an objective spectroscopy unit and a linear polarimetry unit into the imager. The expected depth with a signal-to-noise ratio of 5 is about 20.5 ABmag for 100 seconds exposure at u-band. This enables us to detect a lot of transient objects, such as kilonova emissions from a neutron star merger closer than ~130 Mpc within a day after its collapse.
13096-131
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Las Cumbres Observatory (LCO) operates a global network of robotic 0.4, 1.0, and 2.0-meter telescopes to facilitate scientific research and education in time-domain astronomy. LCO's flagship educational program is the Global Sky Partners (GSP) program, where up to 1500 hours per year of telescope time are awarded to individuals and organizations that run their own, fully supported, educational programs. The GSP has a presence in 40 countries and 45% of the Partners target under-served, under-represented, and developing world audiences.
The obsolescence of the existing 0.4-meter telescope network prompted LCO to update the fleet of 10 telescopes to a new system of off-the-shelf products based on Planewave Delta Rho 350 telescopes with QHY600 CMOS cameras. More than half of the 10 telescopes are deployed and in operation worldwide, with completion of the deployment expected at six of our sites in Q1 2024.
We describe the design and performance of this new system and its components.
We comment on modifications made to the QHY600 cameras, as well as on the treatment of random telegraph noise of its CMOS detectors within our data processing system.
13096-132
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We have developed a simultaneous JHKs bands camera kSIRIUS for the Kagoshima University
1m telescope. kSIRIUS uses three 320x256 pixels InGaAs arrays for astronomy manufactured
at Hamamatsu Photonics, Inc.(Japan) in collaboration with us. These three detectors enable
a simultaneous imaging observation of J, H, and Ks bands. The fields of view are
3.7’ x 2.9’ with a pixel scale of 0.69”. We performed a test observation of kSIRIUS on
the 1m telescope in January 2023. The stellar image is reasonably good compared with the
typical site seeing. We have also obtained the preliminary limiting magnitudes as
J: 16.3, H: 15.3, and Ks: 14.5 (exposure time = 270sec., S/N = 10).
13096-133
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Wide-Field Infrared Transient Explorer (WINTER) is a new near-infrared time-domain survey instrument installed on a dedicated 1-meter robotic telescope at Palomar Observatory in June of 2023. WINTER’s science goals include robotic follow-up of kilonovae from binary neutron star (BNS) and neutron-star black-hole (NSBH) mergers, surveys to study galactic and extragalactic transients and variables, along with building up a deep, coadded image of the near-infrared sky. The project also serves as a technology demonstration for new large-format Indium Gallium Arsenide (InGaAs) detectors for cost-effective near-infrared photometry without cryogenic cooling. WINTER’s custom camera combines six InGaAs detectors with a novel tiled fly’s-eye optical design to cover a >1 degree-squared field of view in the Y-, J-, and shortened-H-band filters (0.9-1.7 microns). In this talk, I will present the design, on-sky performance, and next steps for the newly-commissioned WINTER observatory.
13096-134
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Argus Pathfinder is a new array telescope equipped with extremely-high-speed wide-field cameras and is designed to be an order-of-magnitude increase in our capability to explore the sky at high cadence. This system will perform the deepest high-cadence optical survey with 30-second exposures. In bright time, it will observe at a one-second cadence, pushing into a regime largely unexplored by previous sky surveys. The Pathfinder array is a 2.3 GPix system capable of supporting 38 individual 20 cm aperture F/2.8 telescopes, all housed within a single custom-built equatorial mount contained inside a temperature-controlled enclosure. Pathfinder is the first telescope to implement our new pseudofocal design, with the architecture of its subsystems intended to scale up to support much larger array telescopes, such as the planned 900-telescope Argus Array. Pathfinder was deployed to the Pisgah Astronomical Research Institute in western North Carolina in December of 2022, with commissioning operations done in 2023. Here, we detail commissioning operations, results from telescope alignments, and image performance over the first six months of science operations.
13096-135
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Optical SETI (Search for Extraterrestrial Intelligence) instruments exploring the very fast time domain, with large effective collecting areas and large sky coverages, are particularly well-suited for the detection of optical techno-signatures and astrophysical transient sources.
The Panoramic SETI experiment (PANOSETI) aims to observe optical transients from nanosecond to second precision across a wide instantaneous field-of-view (~100 sq.deg. per telescope pair) by using two or more assemblies of telescopes to reject spurious signals by coincidence detection. On-sky results from pairs of PANOSETI telescopes deployed at Lick Observatory using baselines <700m are presented to evaluate instrument performance and false alarm rates.
13096-136
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Cryoscope Pathfinder is a 16 deg2 FoV infrared telescope, operating in the photometric K-dark bandpass (2.35-2.5 um). Upon commissioning, the Pathfinder will be the widest and deepest NIR imager of its kind. A spherical primary mirror is utilized but unlike classical Schmidt designs, Cryosocope employs two fused silica meniscus lenses at an entrance pupil located just behind the focus, rather than a single transmissive Schmidt corrector located at twice the focal length. The convex meniscus element can support atmospheric pressure, which allows the entire optical path to be evacuated and cooled to 80 K, reducing thermal self-emission, and thereby facilitating an increase of two orders of magnitude in the field of view compared to existing ground based infrared telescopes. We report room temperature performance measurements, which confirm that manufacturing and alignment errors do not significantly compromise the excellent wide-field performance predicted by optical models.
13096-137
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Gamma-Ray Polarimeter (GRAPE) is a wide field of view (FoV) Compton polarimeter measuring γ-ray polarization from transient sources such as Gamma-Ray Bursts (GRBs) in the 50-500 keV energy range with a broad range (20 keV – 3 MeV) for spectroscopy. The instrument is a 7x7x5 array of 245 optically isolated SiPMs each coupled to either a high-Z (GAGG:Ce) or low-Z (para-Terphenyl) scintillator. The novel design provides enables Compton imaging in addition to polarization capabilities, and Co-60 calibration sources (~25 nCi) imbedded within two centrally located low-Z detectors allow for onboard calibrations. We will report on the instrument performance of this design during a test flight on August 27, 2023, from Fort Sumner, NM.
13096-138
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Simons Observatory Small Aperture Telescopes (SATs) are a set of 0.46 meter aperture Cosmic Microwave Background polarimeters that will observe at multiple frequencies between 30 and 280 GHz from the Parque Astronómico Atacama in Chile to search for primordial B-modes. One distinguishing feature of the SATs is a cryogenic (~50K) continuously-rotating half-wave plate that modulates the incident polarization signal to frequencies above the 1/f knee of atmospheric fluctuations. We present initial commissioning results for a mid-frequency SAT with an array of 90/150 GHz dichroic TESs, focusing on initial half-wave plate mechanical, thermal, and optical performance, as well as its signature in the time ordered data.
13096-139
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Our team has recently demonstrated a photonic Quantum-Inspired Imager (QI2) which provides source reconstruction below the optical/NIR diffraction limit in the presence of atmospheric turbulence without the need for adaptive optics. Turbulent cells in the atmosphere reduce image resolution by causing fluctuations in the phase of propagating wavefronts. Rather than relying on conventional methods of wavefront sensing, our approach leverages the spectral diversity inherent in the factors which limit resolution, thus breaking the degeneracy between these aberrating processes. Though this concept has long been employed in astronomy to achieve diffraction limited imaging, our approach achieves this necessary spectral diversity with a passive photonic lantern mode multiplexer that converts a multimode wavefront input into an array of spatially distinct single-mode outputs, from which we can deduce the atmospheric phase variations and reconstruct the source function. We present detailed simulations, laboratory tests, and on-sky results demonstrating the effectiveness of the QI2 approach in measuring atmospheric turbulence and correcting phase distortions.
13096-140
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The EXoplanet Climate Infrared TElescope (EXCITE) is an instrument designed to measure spectroscopic phase curves of extrasolar hot Jupiters from a long duration balloon platform. EXCITE will fly a moderate resolution spectrometer housed inside of a cryogenic receiver actively cooled by two linear pulse tube cryocoolers. Here we provide the current status of the design and performance of the cryogenic receiver, its heat rejection mechanism, and associated control electronics. A recirculating methanol fluid loop rejects heat from the cryocoolers and transports it to sky-facing radiator panels mounted to the gondola. The cryocoolers are controlled by custom drive electronics with active vibration reduction functionality to minimize degradation of pointing stability. We discuss the thermal and vibrational performance of the cryogenic receiver during ground-based pointing tests in its 2023 field campaign in Ft. Sumner, NM.
13096-141
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Our project aims to identify the physical nature of gamma-ray burst (GRB) emission via measurement of the optical spectral shape of this emission during the prompt phase, usually lasting up to 70 sec. These measurements require a fast-moving optical telescope and instrumentation to respond autonomously to real-time GRB alerts. The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTellA-TAO) has a 0.7 m aperture and can point anywhere above the local horizon in 8 seconds. We receive GRB Alerts via an internet socket connection to the Gamma Coordinates Network (GCN) at the telescope site. We measure the GRB prompt optical emission with the Burst Simultaneous Three-Channel Imager (BSTI), which incorporates 3 EMCCD cameras, at Sloan g', r', and i' bands, for simultaneous high time-resolution imaging as fast as a few hundred milliseconds per frame. NUTTellA-TAO is a fully automated telescope. In 2020 and 2023, we observed GRB afterglow starting from 58 and 41 seconds after the BAT trigger. It is the earliest afterglow optical observation with three filters simultaneously.
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REMIR is a NIR camera mounted on the REM telescope at ESO-La Silla Observatory. Soon after its installation in 2003, the REMIR camera went through a series of cryogenics problems, due to the bad functioning of the Leybold cryocooler Polar SC7 and we were forced to change drastically the cryogenics of REMIR, going from cryocooler to LN2, via an ad-hoc modified Continuos Flow Criostat, a cryogenics system developed by ESO. Today, the availability of new generation small cryocoolers, in our case the Sunpower CryoTel GT AVC, allowed us to change again and come back to the original cryogenics for the REMIR camera. The system has been assembled and intensively tested at ESO and at INAF-OAR premises, then it has been mounted on the REMIR camera and tested at working condition. In this paper we report the details and results of the project.
13096-144
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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ArgusSpec, a fully autonomous low-resolution rapid follow-up spectrograph, has been optimized for stellar flare follow-up by prioritizing high speed follow-up, optical efficiency, and wavelength coverage. Stellar flares are challenging transients to follow-up at a large scale due to their spacial and temporal unpredictability and their sub-minute rise in flux followed by an exponential decay. We present performance data from commissioning along with results from operations with a real-time transient alert stream from Argus Pathfinder, located at the Pisgah Astronomical Research Institute in western North Carolina alongside ArgusSpec, and Evryscope North, housed at Mount Laguna Observatory.
13096-145
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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At the Astronomical Observatory of Padova a laboratory test bench has been built to investigate the causes and the possible solutions for the non optimal performance of the Four Quadrant Phase Mask (FQPM) installed on the SHARK-NIR instrument. The FQPM performance have been tested with several configurations including an ALPAO 97-15 deformable mirror. The configurations used in the laboratory, the procedures to align the FQPM and the results are reported in this work.
13096-146
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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MuSCAT3 and 4 are the twin multiband imagers developed for the two 2m telescopes of Las Cumbres Observatory (LCO), Faulks Telescope North (FTN) at Haleakala Observatory in Hawaii and Faulks Telescope South (FTS) at Siding Spring Observatory in Australia. Both instruments have four optical channels each equipped with a 2k x 2k CCD camera, enabling four-band simultaneous imaging. We have developed a new set of narrow-band filters for both MuSCAT3 and MuSCAT4, primarily aiming at probing the sodium D absorption feature (Na D lines; 589 nm) in the atmospheric spectra of exoplanets by means of multiband transit photometry. In this presentation we will introduce these new narrow-band filters and show their on-sky performance.
13096-147
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Wide Field Survey Telescope (WFST) is a 2.5m diameter telescope proposed by the University of Science and Technology of China and the Purple Mountain Observatory. The telescope is located at the summit of the Saishiteng Mountain near Lenghu, Qinghai province.
The WFST is equipped with a mosaic CCD camera located at the primary focus position. This camera consists of 9 scientific imaging CCDs, 8 wavefront CCDs, and 4 guide CCDs. The CCDs are housed within a vacuum dewar, and the electronic signals are transmitted through vacuum dewar connectors to the readout electronic section. The readout electronic system is divided into three main components: the front-end readout board (FEB), the data acquisition board (DAQ), and the power board.
This article will introduce a low-noise CCD readout and high-speed reliable data upload design for the WFST mosaic CCD camera, and give the result of the performance test.
13096-148
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The number of type Ia supernova observations will see significant growth within the next decade, especially thanks to the Legacy Survey of Space and Time undertaken by the Vera Rubin Observatory in Chile. With this improvement, statistical uncertainties will decrease and flux calibration will become the main uncertainty for the characterization of dark energy. The StarDICE experiment proposes to overcome this uncertainty by measuring the spectra of stars from the CALSPEC catalog at the millimagnitude level, and make it the new calibration reference for the LSST experiment.
The StarDICE experiment is currently operating at l’Observatoire de Haute-Provence, and has been taking data since the beginning of 2023. To reach a sub-percent precision, the instrument throughput will be calibrated and monitored with a LED-based artificial star source, calibrated on NIST photodiodes. With slitless spectrophotometric, photometric data and atmosphere simulation, we have been able to adjust the spectra from the CALSPEC calibration at the millimagnitude level. Here, I will present the first results of StarDICE.
13096-149
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Presenting SPIRIT, a ground-based NIR InGaAs CMOS instrument optimised for time-series photometry of late M and L type stars. Using a custom wide-pass filter, SPIRIT minimises atmospheric PWV effects and operates maintenance-free without liquid nitrogen. Compared to a CCD-based instrument, SPIRIT shows better photometric noise performance for L type stars and below, reducing red noise in light curves affected by PWV variability, using on-sky results from the SPECULOOS-Southern Observatory during 2022 – 2023. Limited by detector read noise in most cases, our work suggests future improvements for this instrument type.
13096-150
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The DESI focal plane is one of the most complex astronomical instruments ever constructed. Despite enormous success in the first year of operations, there was evidence during pre-survey operations that showed electronics reliability issues that needed to be addressed in order to improve reliability and to reduce loss of on-sky time. This experience is not unique to DESI since many instruments would benefit from upgrades after installation, but this is only possible if planned for during the design of the instrument. Significant modifications to instruments after first-light can result in a large overhead to on-sky time and potentially present a risk to the hardware. These modifications are often necessary, but the precise details can never be fully known when the instrument is designed and built. It is therefore important to include this future possibility during early planning. Although this possibility was planned for in the DESI instrument design, many lessons were learned that should be considered for future projects.
13096-151
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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We report on performance studies for wavelength calibration using a laser frequency comb and the fiber-fed HIgh Dispersion Echelle Spectrograph (HIDES-F) on the Okayama 188cm telescope. We use a laser frequency comb system that has been recently developed and reported. The comb is based on an erbium-doped fiber-based femtosecond laser and can generate comb-shaped laser modes with a wavelength range of 350nm - 408nm, 453nm - 543nm, and 664nm - 873nm with a mode spacing of 30GHz. The comb has been installed in a room of the Okayama 188cm telescope dome and has been in operation since 2020. The comb spectra were obtained during observations for precision radial velocity (RV) measurements with an iodine absorption for about two years. Using the spectra of the comb and other wavelength calibrators, we have measured instrument shifts of HIDES-F and evaluated its effects on wavelength calibration for precise RV measurements.
13096-152
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Laser frequency combs (LFCs) are optical devices that produce a series of equally spaced spectral lines that can serve as precise and stable references for spectroscopic calibration. ESO has already since several years, laser frequency combs systems in routine operation for the HARPS and the ESPRESSO instruments. We discuss the challenges and solutions for maintaining and operating the LFCs for daily calibrations, and latest achieved performances are presented. Open issues are outlined as well.
13096-153
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The 2-metre Liverpool Telescope will soon be joined by the New Robotic Telescope (NRT), a 4-metre-class, robotic and fully autonomous telescope, at the Roque de los Muchachos Observatory (ORM) on La Palma, Canary Islands, Spain. The 4-metre primary mirror of the NRT will be comprised of 18 hexagonal segments of 1-meter diameter each. All the individual segments need to be perfectly aligned to obtain a paralell wavefront that can be successfully exploited by the telescope instruments. For that, and to get the most out of the NRT, we need an instrument to assist in the alignment of the different segments.
To that end, we designed a wavefront sensor that would be not only reliable and robust (indispensable for a robotic telescope), but also economical, and therefore with as many off-the-shelf components as possible. We chose a Shack-Hartmann type of wavefront sensor, that rests on the use of a lenslet array. The assembly of segments can be mapped onto the array imaged at the telescope pupil by the lenslet array. This will allow us to detect the misalignment of each segment with respect to the other segments, but also the misalignment of the primary mirror with respect to the second
13096-154
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Circumgalactic H-alpha Spectrograph (CHaS) is a new narrowband integral field spectrograph optimized for observing faint emission from the ionized circumgalactic medium (CGM) of nearby galaxies. CHaS is deployed on the 2.4m Hiltner telescope at MDM Observatory in Arizona, where we are conducting an initial science survey collecting deep spectral imaging of 10 galaxies in Ha emission. Here we debut the commissioning of a blue channel, extending the spectral coverage to include H-beta and OIII emission. We present modeling for new narrowband filters that can tilt to center on different wavelengths, expanding our range of observable redshifts while limiting spectral overlap. Finally, we will discuss the development of an actuated lenslet array mount to precisely shift the lenslet array across the focal plane, offsetting instrument flexure. CHaS will be an ideal test-bed for new focal plane and detector technologies as we develop it into a facility instrument at MDM Observatory.
13096-155
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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For accurate photometric observations, it is important to correct for the classical nonlinearity of the H4RG detector system. Previous methods (such as those used in the JWST pipeline) correct for nonlinearity by measuring how a linear signal is converted to a nonlinear one using a stable light source. However, even with a stable light source, this method is not applicable for pixels with non-negligible and nonlinear dark currents. To address this, we devised a new method to correct for nonlinearity in such cases and verified its practicality.
13096-156
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Circumgalactic H-alpha Spectrograph (CHaS) is a ground-based, narrowband optical integral field spectrograph designed to observe ultra-faint extended emission from ionized gas in the nearby universe. Commissioned for use as a facility instrument at MDM observatory, we are currently surveying nearby galaxies to produce deep H-alpha images and velocity maps, complemented with observations in other wavelengths. We present our work developing a robust analysis pipeline for CHaS, providing a toolkit to process images with densely-packed, spatially-resolved spectra. The pipeline includes new techniques for astrometric refinement, wavelength mapping and distortion calibration of arrayed spectral images, as well as manipulations in Fourier space. With these, we are able to optimize our image registration and stacking procedures, sky background removal and spectral cube extraction for the tightly packed microlens array images. We highlight results using 5-10h deep image stacks and demonstrate results from cross-correlation with imaging and spectral data from other astronomical surveys.
13096-157
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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GAOES-RV (Gunma Astronomical Observatory Echelle Spectrograph for Radial Velocimetry) is a high-dispersion echelle spectrograph for the 3.8 m Seimei Telescope at Okayama Observatory, Kyoto University. It covers the wavelength band from 516 to 593 nm and provides reciprocal resolution of 65,000. To maintain both the throughput and wavelength resolution of the observing system, starlight is collected in a 2.4 arc-second diameter field of view at the Nasmyth focus with a multimode optical fiber, and an image slicer is used at the other end of the fiber link. An iodine absorption cell is used for precise radial velocity measurements, and currently a precision of about 2 m/s can be achieved for bright solar-type stars. GAOES-RV has been in operation since July 2023, and is widely used for a variety of scientific observations, including the detection and characterization of exoplanets, stellar abundance analysis, and research on active stars.
13096-158
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Veloce spectrograph is a high resolution (R > 75000), compact, highly-stabilised, and hyper-calibrated echelle spectrograph to obtain Doppler velocities for Sun-like and M-dwarf at <1 ms-1. This spectrograph was built utilising multiple innovations to provide a “just -enough-stabilisation” platform, compensating the science observations with simultaneous collected data from an ultra-stabilised calibration source. The spectrograph consists of three spectral arms, one of which has been in operation since 2018 and the additional two arms undergoing construction. This paper presents a review of the status of the upgrade project along with discussions on the mechanical and optical designs in terms of procurement and manufacturability. We discuss the installation of the the instrument driven from the lessons learned during the construction of the first arm of the spectrograph and the resulting changes to the detector electronics, optical mounts, and infrastructure, also the provisional acceptance of the installed instrument.
13096-159
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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NIRPS is a Near-Infrared Adaptive-Optics-assisted high-resolution spectrograph for the La Silla/ESO 3.6m telescope. The cryogenic spectrograph, operating at 75K, is a fiber-fed cross-dispersed echelle (R4) spectrograph covering a wavelength range of 0.97-1.85 microns simultaneously, with a power resolution of 80,000. After 18 months of AITV phase, the NIRPS spectrograph was shipped via plane to Chile fully integrated with all the optical elements mechanically attached to the optical bench inside the vacuum vessel. During this trip, the spectrograph survives to 20G accelerations. From the validation phase and technical commissioning results, two major modifications were required : 1) the diffraction grating element was removed and replaced by a new etched crystalline silicon and 2) a thermal enclosure was added around the vacuum vessel. In this talk, we will review the final spectrograph performances and describe the novel techniques developed to minimize shipping costs, AITV phase duration, and grating replacement at the observatory. Additionally, we will discuss the thermal enclosure design to achieve the sub-mK thermal stability.
13096-160
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Keck Cosmic Web Imager (KCWI) has been taking excellent integral field spectroscopy of blue wavelengths 350 - 560 nm for the last 7 years. Thanks to the Keck Cosmic Reionization Mapper project, KCWI will now be able to take simultaneous red wavelength data 560 - 1080 nm with configurable spectral resolutions from 500 - 13000 in a field of view up to 20”x33”. We will summarize the red side’s installation, commissioning, new capabilities with the 7 red volume phase holographic (VPH) gratings, and science readiness. The KCRM project team was led by Caltech in partnership with the University of California at Santa Cruz and the W. M. Keck Observatory.
13096-161
17 June 2024 • 17:30 - 19:00 Japan Standard Time
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Astronomical polarimetry is a crucial tool for studying asymmetries, magnetic fields, and scattering in celestial bodies. The photon-starved nature of polarimetry necessitates advanced capabilities on next-gen telescopes like Giant Segmented Mirror Telescopes (GSMTs). In this context, a feasibility study explores adding polarimetric features to the Giant Magellan Telescope's (GMT) Commissioning Camera (ComCam). The 'GMT-Pol' version integrates a waveplate and Wollaston prism, optimizing ComCam's optics for polarimetry. Achieving seeing-limited performance from 0.36-0.95 μm with a 2.5 arc minute field-of-view, the study includes tolerance analysis and polarimetric modeling to understand optical polarization effects introduced by the telescope and instrument.
Session PS2:
Posters - Instrumentation for Extremely Large Telescopes
18 June 2024 • 17:30 - 19:00 Japan Standard Time
13096-162
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the design of the ANDES UBV module, the bluest spectrograph of the ANDES instrument. It is a fiber-fed high resolution, high stability spectrograph, which will be installed on the ELT-Nasmyth platform to minimize blue fibre losses from the focal plane to the spectrograph. In this paper we present the status of development of the spectrograph, its optical design, and auxiliary devices like exposure meter and leveling system, at the preliminary design stage. As stability is the prime design driver, a thermal enclosure is provided to keep temperature of the optical train stable at ambient conditions, and the pressure is kept constant at high vacuum level. The science, sky background and simultaneous calibration light is fed to the spectrographs via fiber bundles of 66 fibres, which are arranged in a straight row forming the spectrograph slit.
13096-163
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The calibration units of today's instruments are often limited by the fact that a reference source can feed one or even two outputs without having much loss. As a result, there is often a trade-off between throughput and system size to be made.
We have designed a novel Light Distribution System based on pneumatic actuators that allows a defined number of sources to be selected and several outputs to be fed at the same time.
13096-164
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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ANDES is a high-resolution spectrograph to me mounted on one of the Nasmyth foci of the ESO Extremely Large Telescope in Chile. This instrument will be composed of (at least) three spectrographs to cover a high spectral range: one for BV-band, one for RIZ-band, and one for YJH band. ANDES will provide a spectral resolution of ∼100,000 with a minimum simultaneous wavelength coverage of 0.4-1.8 µm with the goal of extending it to 0.35-2.4 µm with the addition of a K-band spectrograph.
A Front End will be installed on the Nasmyth platform with the key functions to support the different sub-units at the Nasmyth focus, to provide selection of the different observing modes, to perform sky rotation during observations, and to manage fiber bundles and cables distribution. As for the seeing limited arms, its key functions are to separate the bandwidth of each spectral arm, provide atmospheric dispersion correction, provide guiding and field stabilization, and to provide calibration source light injection.
In this paper, the preliminary design of the ANDES Front End will be presented. The preliminary optical and optomechanical design of the seeing limited arms will also be detailed.
13096-165
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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ANDES is a powerful new spectrograph that will be installed on the ELT. It will allow astronomers to study a wide range of astronomical objects with unprecedented precision and sensitivity. The instrument is highly complex, but its sophisticated and modular design will enable next-generation astronomy research. This proceeding will describe the design of the instrument developed in the Phase B-one.
13096-166
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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ANDES is a high resolution spectrograph for the ELT, with the goal of providing simultaneous spectra with R~100000 from 0.35 to 2.4 micrometer. The baseline of the instrument covers 0.4 -1.8 micron. Here we present the study on the extension into the K-band (1.95 to 2.45 micron) with its scientific motivation and the technical solution. The spectrograph design is constrained by external limits, but a solution is found that enables key science cases in this wavelength range and closes the gap in ELT high resolution spectroscopy between the ANDES baseline and the METIS instrument. The spectrograph design is throughput-optimized and is fed by the diffraction-limited input from the ANDES SCAO system. We summarize the preliminary optical and cryo-mechanical design. But, as the available mass is one of the critical parameters, we also look into an alternative implementation of the spectrograph with carbon fiber vessels.
13096-167
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The first generation of ELT instruments includes an optical-infrared High Resolution Spectrograph, ANDES (ArmazoNes high Dispersion Echelle Spectrograph). The optical design and architecture of ANDES is primarily dictated by its high spectral resolving power (R=100'000), the area of the spectrograph slit projected onto the sky (> 1 arcsec²), its broad wavelength coverage and the large primary mirror of the ELT, and must foresee several huge fiber-fed spectrograph units. One of them is the RIZ spectrograph, covering wavelengths from 620 to 960 nm. It deals with a recomposed ~40-mm-long entrance slit and a pupil anamorphic magnification to overcome the limitation size of a mosaic 1.6-meter R4 Echelle grating. It requires two fast cameras with F/# close to unity.
This paper describes the preliminary optical design of the RIZ spectrograph instrument, its challenges, and its nominal and expected performances.
13096-168
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the Exposure Time Calculator (ETC) in development for ANDES, the high-resolution optical-infrared spectrograph for the Extremely Large Telescope. The ETC is a tool to predict the performances of the instrument for different parameters and environmental conditions. For these reasons, it is extremely useful in several stages of the project, from the design of the instrument to the preparation of the observations.
13096-169
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The ArmazoNes High Dispersion Echelle Spectrograph, or ANDES, will be a second generation instrument designed for use at the ELT (Extremely Large Telescope). As a fiber-fed echelle spectrograph, it consists of three spectral arms which cover a wavelength range of 0.4 up to 1.8 μm, and the potential to extend its coverage from 0.35 up to 2.4 μm. This versatile instrument delivers an impressive spectral resolution of approximately 100,000, allowing for highly sensitive observations of astronomical objects phenomena, including exoplanets, fundamental scientific inquiries, and various cutting-edge research applications in the field of astronomy. This work will describe the opto-mechanical design of the three cameras inside the YJH spectrograph. The mechanical design is based on an improved strategy already used in instruments like WIRCAM and NIRPS. The optical design is a very performing and simple design as it uses the same four lenses for each band (Y, J and H). The overall expected performance will also be presented.
13096-170
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The first generation of ELT instruments includes an optical-infrared high resolution spectrograph, formerly indicated as ANDES (ArmazoNes high Dispersion Echelle Spectrograph).
The Fiber-Link subsystem carries and redistributes the light from the telescope to the spectrometers via several selectable optical paths that in turn define the baseline observing modes of the instrument.
With this work, we describe the design evolution and challenges of the Fiber-Link module including the reasoning for selected solutions and explaining how requirements are met.
First results from laboratory test and prototype activities are also shown.
Finally, we summarize the compliance against the science top-level requirements and the issues to address moving forward.
13096-171
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present here the preliminary design of the RIZ module, one of the Visible spectrographs of the ANDES instrument. It is a fiber-fed high-resolution, high-stability spectrograph. Its design is following the guidelines of successful predecessors like HARPS and ESPRESSO. In this paper we present the status of the spectrograph at the preliminary design stage. This is a warm, under vacuum thermally controlled and fiber fed echelle spectrograph. Following the design of the phase A, the huge etendue of the telescope is reformed in the instrument with a long slit made of smaller fibers. We discuss the system design of the spectrographs, and its exposure meter.
13096-172
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The RIZ & UBV visible spectrographs of the ANDES instrument, which are foreseen to be installed at the Extremely Large Telescope, require to be under a stable high vacuum and at an extremely stable temperature of 1mK to reach the radial velocity goal of 20 cm/s RMS over a 10-year period. The baseline design, integration, first analysis of the 5t aluminum vacuum tank, vacuum system and the double insulation layer thermal shield of the two room temperature ANDES’s spectrographs, RIZ & UBV, is presented in this paper. A very analogous configuration is proposed for both instruments in view of their similarities even if RIZ is located in the Coudé room and UBV on the Nasmyth platform. In addition, this article addresses the non infinite rigidity of the nasmyth platform and its consequences on the instrument design.
13096-173
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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This paper describes the progresses in the design of the Integral Field Unit (IFU) module of ANDES. the unit consists of a series of submodules that work in synergy with each other and with the rest of the telescope, primarily the Single Coniugate Adaptive Optic (SCAO) module, which will allow for different zoom values by creating four different spaxel scales 5mas, 10mas, 30mas and 100mas. These scales will be used to feed the fibre link connected to the output of the IFU module, realizing the different observing modes with size matched to the spectrometer aperture. The article also illustrates the drawings of the field re-rotator, the guider, the Atmospheric Dispersion Corrector and a system of screens useful for observing objects close to the star.
13096-174
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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Curvature wavefront sensing (CWFS) is a method used in adaptive optics to estimate the wavefront in an optical system, using a pair of equally defocused images. We describe the use of CWFS in measuring the aberrations in the red camera lens of G-CLEF, a high resolution optical echelle spectrograph for the Giant Magellan Telescope (GMT). We investigated the practical considerations and limitations of CWFS for metrology. CWFS was used to estimate the amplitudes of the Zernike modes representing the wavefront, using real defocused images taken in the lab and simulated defocused images from a Zemax model. We then compared the results with the actual Zernike mode amplitudes computed by Zemax, finding that higher-order Zernike mode amplitudes were correctly estimated within less than 0.1 waves. When implemented carefully, CWFS was useful in characterizing the aberrations present in G-CLEF’s red camera during assembly, integration, and test.
13096-175
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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G-CLEF is a high-resolution stabilized spectrograph designed for the Giant Magellan Telescope (GMT). Prior to deployment on the GMT, the instrument will be coupled to the Magellan Clay telescope for a period of 5 years (the G@M phase). While the spectrograph does not require any modifications, the front end (FE) required to couple G-CLEF to the Magellan telescope is a dedicated new system. G@M will offer three seeing-limited observing modes: high resolution (R~150K), extreme high resolution (R~350K), and high transmission (R~75K). A fourth observing mode will enable feeding the instrument through the Magellan novel adaptive optics (AO) platform, MagAO-X. To ensure stable, high-quality images on the science fiber face, the seeing limited FE will include atmospheric dispersion correction (ADC), acquisition and field guiding camera, fiber inspection modules, and on-target guiding coupled to a fast tip/tilt mirror for high-frequency vibration damping (sampling at ~600Hz and correcting at ~150Hz). In addition, the FE unit will include calibration source injection modules, a pupil slicer, and a double scrambler.
13096-176
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The GMT-Consortium Large Earth Finder (G-CLEF) is a fiber-fed, optical echelle spectrograph that will be a first light instrument for the Giant Magellan Telescope (GMT). G-CLEF is a general-purpose echelle spectrograph with precision radial velocity (PRV) capability. G-CLEF completed its Critical Design Phase for GMT in 2018. G-CLEF’s challenging technical requirements drove the decision to use low-CTE composites for the optical bench and several optical mounts including M1, M2, and its grating mounting structure. This paper discusses the benefits and challenges of using composites in a ground-based instrument as well details of their implementation in the G-CLEF instrument.
13096-177
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The GMT-Consortium Large Earth Finder (G-CLEF) is a designed fiber-fed, optical echelle spectrograph (350 to 950 nm) that is to be a first light instrument for the Giant Magellan Telescope (GMT). The G-CLEF spectrograph optical train separates the blue (350 to 535 nm) and red (535 to 950 nm) channels. The 7-element red camera has been assembled and is undergoing testing which measures three performance metrics: 1) Interferometric Double-Pass, 2) Camera Stand-alone, and 3) VPH + Camera. Interferometric double-pass measures the total on-axis wavefront error, while the Camera Stand-alone and VPH + Camera tests will inject different wavelengths of light spanning the channel bandpass at their design trajectories and input/output locations. The full width at half maximum for each wavelength will be measured at optimal focus. By taking images at equally defocused planes, the curvature wavefront sensing technique was used to estimate system aberrations to verify requirement compliance.
13096-178
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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This project aims to formulate, design , build and test a versatile, high-efficiency, low-resolution spectrograph to function as the G-CLEF exposure meter. G-CLEF, the first-generation Giant Magellan Telescope's (GMT) instrument, is a state-of-the-art, high-resolution, echelle spectrograph for the GMT, expected to be completed for the telescope's first light. The exposure meter plays a vital role for adjusting barycentric corrections of Doppler radial velocity (RV) by accounting for t Earth's chromatic atmospheric influences. Its significance becomes pronounced in Extreme Precision RV (EPRV) measurements, where the atmosphere's wavelength dependency contributes to errors at the scale of tens of centimeters per second, the same level of precision required for detecting Earth-analog planets orbiting stars similar to the Sun, aligning with one of the primary scientific objectives of G-CLEF. This paper details the optical and mechanical designs, grounded in the principal requirements that have been previously validated through design trade-off analysis and performance simulations. Additionally, we update the current stage of assembly and test phase of the exposure meter prototype.
13096-179
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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GMTIFS a near-infrared Integral-Field Spectrograph instrument is being designed for the Giant Magellan Telescope. This instrument contains precision mechanisms that must operate in a cryogenic vacuum. The positioning control system requires high precession resolvers that can operate under these challenging operating conditions. A prototype mechanism has been manufactured to validate a capacitive displacement sensor-based resolver system. This poster will report on the performance results of the capacitive displacement sensors and the resolver system under representative cryogenic vacuum conditions expected within the final GMTIFS cryostat.
13096-180
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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This work explores the method and design impact of a mechanical stability analysis for the GMTIFS instrument, with a focus on the deflection of the cold stop, in the context of the motion of the optical table inside the cryostat mounted to the instrument platform. Understanding this deflection will inform design of the instrument mounting points and especially the final design and size of the cold stop.
13096-182
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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We introduce an optical system design of the calibration system for Giant Magellan Telescope Near-Infrared Spectrograph (GMTNIRS), covering a wavelength range of 1.08 - 5.4 μm. The calibration system serves multiple purposes, including flat fielding, wavelength calibration, dark tests, and focusing of the spectrograph. It comprises a flat source collimator, illuminator, relay optics, and three targets – the USAF 1951 resolution target, a pinhole, and a dark mirror. The F-ratio of the output beam in image space is designed to be 8, replicating the Giant Magellan Telescope’s illumination. The flatness of the light from the calibration system is simulated using a non-sequential ray tracing method, with the results indicating >99% flatness across the slit area.
13096-183
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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HARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 450nm to 2450nm with resolving powers from 3500 to 18000 and spatial sampling from 60mas to 4mas. It contains four identical spectrograph modules that collimate, disperse, and image the long slit at the exit of the IFU onto the science detectors. The collimation optics comprises of a three mirror anastigmat, using off-axis, aspheric mirrors. Previously we simulated an iterative alignment procedure that uses interferometric wavefront error measurements together with a numerical optical model to optimise the wavefront error and adjust a set of compensators.
In this paper we demonstrate the feasibility of this procedure with an off-axis parabola as a prototype collimator that has the same number of compensators as the HARMONI collimators, and show that we achieve a sufficiently low wavefront error within a few iterations of alignment. Additionally we cool the test setup in a cryostat and measure the wavefront error in vacuum and at cryogenic temperature to demonstrate the athermal design of the prototype at its operating temperature of 130K.
13096-184
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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Design and Functional description of the Calibration Module (CM) of the HARMONI Instrument for ELT Telescope, which includes all the functionalities necessary to remove the instrumental signature from the observed science data,perform the technical calibrations needed to set up other sub-systems, and for monitoring the health of the instrument during operations.
13096-185
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The integral field spectrograph is a key sub-system of HARMONI instrument, which forms the 2D spectral image and projects it onto the scientific detector. It has 40 operational modes with different platescales and gratings covering the band of 810-2400 nm with three resolution grades. In each of this configurations the as-built spectrograph wavefront error is strictly limited. We perform the inverse sensitivity analysis for measurable and unknown errors and build the errors budget on this basis. Then we correct the values for the actual technological limits and perform a double-stage Monte-Carlo analysis, which includes two scenarios of alignment simulation. Eventually, we show that it is possible to reach the target image quality of the entire instrument with practically feasible spectrograph tolerances.
13096-186
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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HARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 470nm to 2450nm with resolving powers from 3300 to 18000 and spatial sampling from 60mas to 4mas. It can operate in two Adaptive Optics modes - SCAO (including a High Contrast capability) and LTAO - or with NOAO. The project is preparing for Final Design Reviews. Combined with the SCAO, a high-contrast imaging capability is implemented to spectrally characterize young giant exoplanets or young circumstellar disks, with contrast down to 1e-6.For a sake of space available in the instrument, the three sub-assemblies of the HCM are distributed in the instrument. These conditions force us define a specific integration process based on a specific integration tool used to mount, align and validate the module in Europe before its integration in the instrument. This paper describes the integration strategy adopted for the HCM. After a fast description of the module itself, we will detail the strategy and the tools defined to manage the integration. Finally, we will describe the tests planned on the system to validate the performances before installation in Harmoni.
13096-187
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Instrument Control Electronics subsystem at HARMONI is responsible, among other things, for providing suitable housing for all electronic control devices while fulfilling the established requirements for the instrument. Given the small volume available for the instrument, the surface available for the electronic cabinets is limited as well as the height of some of them. In addition, controlling tightly the amount of heat transmitted from the cabinets to the environment leads to find a bespoken solution for this issue. This paper presents the overall design of the cabinets with emphasis on temperature analysis and insulation technologies.
13096-188
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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HARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 470nm to 2450nm with resolving powers from 3300 to 18000 and spatial sampling from 60mas to 4mas. It can operate in two Adaptive Optics modes - SCAO (including a High Contrast capability) and LTAO - or with NOAO. It expands the discovery space of the 39 m Extremely Large Telescope (ELT) through a powerful combination of vast collecting area and exquisite spatial resolution (as high as ~10 milli-arcsec in the best conditions). This resolution means HARMONI will revolutionize our understanding of the physical properties, chemical composition, kinematics and dynamics of many astrophysical sources, including the most distant galaxies in the primeval Universe. In this paper we report on the updated science performance predictions, using the most up-to-date model of the instrument within the HARMONI Simulator (HSIM), for a set of well-defined HARMONI reference science cases tackling some of the fundamental open questions in many diverse areas of astrophysics.
13096-189
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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HARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 470nm to 2450nm with resolving powers from 3300 to 18000 and spatial sampling from 60mas to 4mas. It can operate in two Adaptive Optics modes - SCAO (including a High Contrast capability) and LTAO - or with NOAO. The project is preparing for Final Design Reviews.
The IAC, as an institution participating in the consortium responsible for the design and manufacturing of HARMONI, is in charge of the pre-optics system. This large-scale subsystem requires a cryogenic test bench capable of accommodating it. At this point, the HIPOTEC cryostat comes into play.
A Beckhoff PLC automates this large-scale cryostat. A Touchscreen panel or web browser carried out the operation, allowing for remote control. This system utilizes the TwinCAT PLC HMI Web.
This PLC automates all the control processes of the cryostat, allowing the cryogenic cycle to perform automatically with just one click. It carries out this entire process safely using a state machine capable of bringing the system into operation.
13096-190
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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Specsim is a Python package for simulating spectroscopic observations with TMT-MODHIS and Keck-HISPEC, which are both high-resolution (R~100,000) diffraction-limited spectrographs each covering y, J, H, and K bands simultaneously. The simulators compute the total number of photons arriving at the detector per second and the noise level as well as the associated photon-limited radial velocity precision per order and cross-correlation function signal-to-noise ratio (SNR). A web platform for Specsim is in development to serve the broader community. The platform aims to provide users of TMT-MODHIS and Keck-HISPEC an exposure time calculator and simulated spectra for planning observations with the instruments across varied observing scenarios and science cases.
13096-191
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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IRIS (InfraRed Imaging Spectrograph) is one of the first light instruments for the Thirty Meter Telescope which, with the help of adaptive optics, offers diffraction-limited near-infrared imaging and integral field spectroscopic capabilities. The Imager optics design was based on four Teledyne H4RG-10 detectors with a pixel size of 10 microns. However, due to the cost and schedule uncertainty related to acquiring 64-channel H4RG-10 detectors which arose in the IRIS Final Design Phase, a re-design of the optics to work with H4RG-15 detectors was initiated to investigate a possible new baseline. This paper describes the optical design of the IRIS Imager with H4RG-15 detectors, tolerance analysis, stray light analysis, and the alignment plan.
13096-192
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Mid-infrared ELT Imager and Spectrograph (METIS) is one of the three first-generation science instruments for the ELT. It passed its final design review in Fall 2022. Here, we present the final design of the METIS high-contrast imaging (HCI) modes. We report on the on-going manufacturing and tests of individual HCI components, and outline our plans for system-level integration and tests. Using end-to-end simulations, we predict the performance that will be reached on sky by the METIS HCI modes in the presence of environmental and instrumental error sources, and briefly review the expected scientific application of these modes.
13096-193
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Imager subsystem of METIS (the Mid-infrared ELT Imager and Spectrograph) provides diffraction-limited imaging capabilities and medium-resolution spectroscopy over the full wavelength range 3 to 13 microns.
This Imager has a collimator that feeds two cameras: L&M bands and N band. It has also a precise pupil re-imaging optics.
The collimator and the two cameras are Three-Mirror Anastigmat systems. All mirrors’ surfaces are freeform defined as Zernike surfaces, on post-polished Aluminium.
The Imager works at 40 Kelvin to provide detector-limited performance in both bands, while the fore optics of METIS operates at 70 Kelvin. Therefore, a kinematic mounting has been implemented to allow the temperature difference but at the same time keeps the optics aligned to the challenging accuracy required for high contrast imaging.
We will present the Optics design, the final opto-mechanics and their ongoing manufacturing at Fraunhofer Institute for Applied Optics and Precision Engineering (IOF).
13096-194
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The ELT METIS is the mid-infrared instrument for the ELT providing high contrast imaging and integral field unit (IFU) spectroscopy and normal slit spectroscopy. Inside the common optical path, they are 4 wheels: two in the pupil plane and two in the focal plane. They are included to accommodate the atmospheric dispersion correctors, the field apertures, cold stops, slits, vortex phased masks and the pickoff optics for the L and M band spectrograph (LMS). Among the requirement, the repeatability for the LMS pickoff wheel positioning is particularly tight and a special hinge structure is used to reach the goal. In this paper, we will report on the design and the initial integration results of the METIS wheels.
13096-195
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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After the satisfactory Final Design Review (FDR) towards the end of 2022, the development of the WCU subsystem of METIS is currently in the manufacturing/procurement phase along with the integration of sub-assemblies. We provide an overview of the development of the WCU subsystem at this phase of the project including the progress on the manufacturing of custom components and the details on the compliance with the design principles with a primary focus on the mechanical aspects. Furthermore, we discuss the perspectives and the planning towards the full integration and testing of the full subsystem, foreseen to start within the third quarter of 2024.
13096-196
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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Within the international METIS consortium, the University of Cologne is responsible for the design, manufacturing, integration, and qualification of the Warm Calibration Unit (WCU) subsystem of the instrument. This paper details the final optical design and analysis of alignment optics used for alignment checks during AIT & AIV utilizing a CMOS camera. The paper introduces the novel design concept of aluminum spherical mirrors employed in the main optical train of the WCU. We will also present a brief overview of alignment verification procedures of the Offner relay optics of the WCU sub-system. Finally, the laboratory test results will be presented, showcasing the performance of the CMOS camera and the prototyping of wavefront error measurements of spherical mirrors.
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The Mid-Infrared E-ELT Imager and Spectrometer (METIS) for the Extremely Large Telescope in Chile, is expecting to begin the system-level Assembly, Integration, and Testing (AIT) at Leiden University in 2025. One of the key success factors for the AIT is the preparation of specialized Support Equipments (SEQs). This paper presents the SEQ units developed by ASIAA, including the AIT support frame (ASF), ASF transportation container, clean area system, and AIT lifting platform. The key requirements, functionality, and considerations for SEQ design, along with the simulations, analysis and final products, are provided.
13096-198
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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METIS is a first light infrared instrument for the new ESO/ELT telescope. It includes a cryostat with a mass around ten tons that must face the telescope optical beam placed 6m above the telescope Nasmyth platform, where the instrument is to be mounted. To overcome this height and allow the overall alignment of the field and pupil of the entrance beam we have designed, analysed and optimised a large size structure that is being manufactured. To minimize the overall mass, the beam attachments do not fit in a vertical/horizontal grid but are oblique in a 3D structure. In building this structure one needs to combine 3D cnc machined parts of reasonable dimensions with several welded structural tube structures that, due to the sizes involved, must be manufactured accurately within an angle tolerance of 0.1 degrees. It must be welded using an heavy dedicated template that holds the system in place, regardless of welding induced stresses, until the thermal treatment procedures are applied. This approach together with the rod-end terminated trusses involved in other subsystems are dicussed.
13096-199
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Imager sub-system for the ELT-METIS will provide diffraction-limited capabilities at 3 - 13 microns with a field of view of approximately 11 x 11 arcsec in two channels: LM-band and N-band.
The Imager has passed its final design review (FDR) and started its manufacturing, assembly, integration and verification (MAIV) phase. We present the process of MAIV from final design to end-to-end verification, grouped in three phases: Acceptance tests of components, alignment tasks and verification of requirements. Including a detailed description of selected alignment steps as well as the design of a dedicated test cryostat for the cryogenic verification tests.
13096-200
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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In early 2025, the initial sub-systems for METIS, the Mid-Infrared E-ELT Imager and Spectrometer, are anticipated to reach the system-level Assembly, Integration, and Testing (AIT) facility at Leiden University. The AIT process is projected to extend over nearly three years, encompassing the receipt, integration, verification, and provisional calibration of all METIS sub-systems. Throughout this period, the comprehensive testing and calibration of the entire METIS system will be conducted.
The preparation for integration encompasses diverse aspects, including the planning of various assembly, integration, and verification steps. This involves the development of the integration facility, provision of support equipment, and ensuring the readiness of all requisite software to facilitate the instrument's efficient qualification. This paper describes the system-level assembly, integration, and verification processes of METIS, both in Europe and upon its delivery to the telescope. It will touch on the planning, sequencing of events, necessary facilities, hardware tools, and software tools, emphasizing those elements that are characteristic of the METIS project.
13096-201
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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One of the Nasmyth platform of the ELT will host the AO module MORFEO and the MICADO camera. The light coming from the telescope is processed by the adaptive optics and then sent to the camera. Due to this, a light beam coming from MORFEO and going to MICADO need a special tube in order to preserve this light beam in a controlled environment. A tower with a “thermal tube”, both decoupled from the MORFEO and the MICADO structures, has been designed with this purpose. The paper reports a trad-off analysis between different design in order to fulfill the structural and the seismic requirement of the ELT.
13096-202
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the optical design of the MICADO relay optics, and its alignment procedure. This subsystem consists of six large mirrors that must be aligned to submillimetric and sub-arcminute precisions. We start by introducing the alignment plan, and we perform a simulation of the alignment procedure where we successfully compare its results with the nominal design and tolerances. Afterwards we test the feasibility of the procedure by aligning small dummy mirrors using the final mounts. The results are very promising, indicating the effectiveness of the complete alignment procedure.
13096-203
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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MICADO, the European Extremely Large Telescope first light imager will feature a dedicated high contrast imaging mode specifically designed for observing and characterizing exoplanets and circumstellar disks. Two sparse aperture masks (SAM) will be included, consisting in opaque masks with a set of holes arranged in a non-redundant configuration. Pupil masking transforms a monolithic telescope into an interferometer, with the aim of recovering spatial information down to the diffraction limit of the telescope and below, even in presence of residual aberrations (turbulent AO residuals, non common path aberrations). Two designs have been chosen, with a complementarity in terms of sensitivity and spatial frequency coverage for image reconstruction. In this contribution, the technical choices will be detailed and we will also report on simulations performed to assess the expected capabilities of this mode, with application examples of close companion detection and contrast curves.
13096-204
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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MICADO is the Multi-AO Imaging Camera for Deep Observations, a first light instrument for the Extremely Large Telescope (ELT). The instrument will be assisted by a Single-Conjugate Adaptive Optics (SCAO) system and the Multiconjugate adaptive Optics Relay For ELT Observations (MORFEO). MICADO can operate in the so-called stand-alone mode in the absence of MORFEO with the SCAO correction alone. The Relay Optics (RO), is the optical system relaying the ELT focal plane to an appropriate position inside the MICADO cryostat for that SCAO-only stand-alone observing mode. After successfully passing the Final Design Review (FDR), the manufacturing of the RO is in full swing. We present here the current status of the ongoing assembly, integration and verification campaign, together with its upcoming challenges.
13096-205
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Main Selection Mechanism (MSM) is the cryogenic mechanism that will allow to switch between the 4 operational modes of MICADO, the first light instrument for the ESO Extremely Large Telescope (ELT). It will be located inside the MICADO cryostat and operate under vacuum conditions at cryogenic temperatures. The mechanism consists of a main support structure and a rotating platform, where the MICADO Low Resolution Imager, Spectrometer and Pupil Imager modules are located. Manufacturing and procurement activities for the MSM started in late 2022. In this paper we present the current status of manufacturing and procurements for the MSM, and its overall assembly, integration and test (AIT) plan. AIT activities will start in 2024, and will be concluded with the cryogenic test of the mechanism inside the USM Big Test Cryostat, before the delivery of the mechanism to the MICADO lead Institute, MPE, for its integration inside the instrument cryostat.
13096-206
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Universitaets-Sternwarte Muenchen (USM) was responsible for the procurement of a big Liquid Nitrogen (LN2) continuous-flow test cryostat, equipped with a 1600 diameter optical bench. This cryostat is planned to perform cryogenic tests of the two large cryogenic mechanisms of the MICADO instrument, the Main Selection Mechanism (MSM) and Central Wheel Mechanism (CWM), and of some of the instrument cold optics (COI) modules.
The Big Test Cryostat was delivered at the end of 2021, and is currently installed at the Max Planck Institute for Extraterrestrial Physics (MPE) laboratories. In this paper we present the design, specifications and measured cold performances of the cryostat. We also provide an overview of the tests planned inside the cryostat, which will start at the beginning of 2024 and will run until the end of 2025, when the mechanisms and the cold optics modules will be finally integrated inside the MICADO Instrument Cryostat.
13096-207
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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MICADO is scheduled to be a first-light instrument installed at the ELT. Herein, we describe the final design and current progress toward hardware completion of the MICADO Calibration Assembly. We discuss preliminary test results of the three individual calibration units as-built and outline the next steps toward delivery at the telescope.
13096-208
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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SHARP is a near-IR (0.95-2.45 mu) spectrograph designed for the 2nd port of MORFEO@ELT. SHARP is composed of a Multi-Object Spectrograph, NEXUS, with robotic slit mask system (~30 slits, 2.2” length) operating over an AO corrected field of ~1.2’x1.2 (35 mas/pix), and a multi-Integral Field Unit, VESPER, composed of 12 probes (1.7”x1.5” each, 31 mas/pix), deployable over an AO corrected area of 21”x58”. MORFEO-SHARP will allow us to study the nearby and the early Universe in unprecedented detail, resolving the physical properties of the first galaxies and the star forming regions within galaxies far back in cosmic time, as well as providing the spectra of individual nearby young stellar objects. The scientific rationale behind SHARP and its features will be presented. SHARP site
http://www.brera.inaf.it/sharp and/or https://sites.google.com/inaf.it/sharp
13096-209
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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"The alignment and the integration of each MORFEO optomechanical system is defined with a mechanical joints that will provide repeability and the posibility to align the optics. This proceeding will analise the machanical system, the way that permits to align the optics and the test on the connections. The test consider a dummy aluminum plate that simulate the optomechaincal element, that is conected to the lower plate rappresenting the MORFEO main structure. The kinematics connection used are of two differnet kinds. the first set of kinematic elements consists in sphere, cylinder and plane. the second set it is composed by three identical half sphere half cylinder connection. The performed test will permit not only to determine the repeatability of the system but also the cabability to the alignment system to provide the correct range and resolution to the optomechanics.
"
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MORFEO (Multi-conjugate adaptive Optics Relay For ELT Observations), formerly known as MAORY, will play a crucial role in deploy a corrected Field of View to ELT instruments. To allow the wavefront sensing, a Laser Guide Stars (LGS) channel is foreseen composed by two subsystems: an objective to materialize a monochromatic (sodium layer wavelength) focal plane (the LGS Objective, LGSO) and the proper LGS wavefront sensor system (LGSWFS).
Here we report about the LGSO optical design, reviewing the requirements, summarizing the geometrical and optical properties of LGSO elements and discussing the expected performances, both for the nominal system and tacking into account tolerances.
13096-211
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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MORFEO (Multi-conjugate adaptive Optics Relay For ELT Observations, known as MAORY), is the Multiconjugate Adaptive Optics (MCAO) relay for the Extremely Large Telescope (ELT) that will provide diffraction-limited optical quality to two instruments at the ELT Nasmyth Platform. MORFEO has officially passed the Preliminary Design Review in February 2023 and it is entering the final design phase. The general overview of the mechanical design for the MAIN STRUCTURE described in this paper is an updated version of the configuration presented for the Preliminary Design Review in the first half of 2021.
13096-212
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Multiconjugate adaptive Optics Relay For ELT Observations (MORFEO), an adaptive optics module for the ESO Extremely Large Telescope, has officially entered the Final Design phase. The control electronics functions, power and network distribution, system management and monitoring are all part of the MORFEO Instrument Control Hardware. It is based on industrial COTS components, and most of its functions are managed through the use of a PLC-based architecture. The EtherCAT protocol also allows great flexibility in the choice of the PLC modules topology.
This paper describes the current, up-to-date design of the Instrument Control Hardware, and the general rules developed for the design of each MORFEO subsystems control electronics, in order to optimize the architecture while in compliance with ESO requirements.
Finally, an overview of the expected steps that will be taken to bring all aspects of the overall design to a Final Design maturity level is given.
13096-213
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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MORFEO is an adaptive optics module able to compensate the wavefront disturbances affective the scientific observation. It will be installed on the straight-through port of the telescope Nasmyth platform to serve the first-light instrument MICADO and with the provision for a future second instrument. The module successfully passed the Preliminary Design Review in 2021 and is currently in the Final Design phase.
In this paper we present the status of the Thermal Control System (ThCS) with a focus on the thermal and cooling circuits design. The result of the prototyping and the prototyping plan foreseen for the future to validate this circuit are also foreseen.
13096-214
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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MOSAIC is a versatile multi-object spectrograph that will use the widest possible field-of-view provided by the ELT (Extremely Large Telescope). It will have three operating modes that cover observations in visible and infrared light for more than a hundred sources simultaneously by three hundred positioners on the focal plane. The larger size of the patrol area does not allow the use of optical fibers and the light of the pointed galaxies is send to the fiber bundles through the hollow arms of the positioner. An optical relay composed of several mirrors and lenses is integrated inside the arms and routes the light to the fiber bundles located in the base of each positioner. This solution has the advantage that a local ADC (Atmospheric Dispersion Corrector) can be directly integrated in the base of the positioner in front of the fiber bundles. Composed of two rotating prisms, the dispersion of the different wavelengths is corrected and the whole light spectra is re-focalized in the fiber bundles.
13096-215
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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MOSAIC is the multi-object spectrograph (MOS) for the ESO 39m European Extremely Large Telescope (ELT) approved to enter phase B beginning 2022. MOSAIC combines visible and near-infrared channels, from resolved stars up to the most distant galaxies, with multi-object and multi-integral field spectroscopy capabilities. The 2 identical NIR-spectrographs are sub-systems of the NIR-channel, led by the Universidad Complutense de Madrid (UCM, Spain). Each spectrograph includes 3 camera modules delivered by the Laboratoire d’Astrophysique de Marseille (LAM, France) and equipped with Teledyne H4RG science detectors (4kx4k, 15 μm pixels). The 3 modules offer the spectral coverage of the three observing bands YI (0.77-1.06 μm), J (1.01-1.40 μm) and H (1.4-1.85 μm) with spectral low-resolution (approx. 5000) and high-resolution (approx. 9000 in the YI band and 18000 in the H band) capabilities. This paper presents the preliminary optical concept/design of the NIR spectrographs.
13096-216
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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MOSAIC is the multi-object spectrograph (MOS) for the ESO 39m European Extremely Large Telescope (ELT) approved to enter phase B beginning 2023. MOSAIC combines visible and near-infrared channels, from resolved stars up to the most distant galaxies, with multi-object and multi-integral field spectroscopy capabilities. The NIR-spectrograph (130K-90K) is one sub-system of the NIR-channel, led by the Universidad Complutense de Madrid (UCM, Spain). It includes six camera modules delivered by the Laboratoire d’Astrophysique de Marseille (LAM, France) and equipped with Teledyne H4RG science detectors (4kx4k, 15 μm pixels). The six modules distribute two identical cryogenic benches ensuring, on each, the spectral coverage of the three observing bands I (0.77-1.06 μm), J (1.01-1.40 μm) and H (1.4-1.85 μm). This paper presents the design of a cryogenic NIR camera prototype based on an athermal concept and details the ongoing AIT development for verification in the 0.77-1.063 µm domain in relevant environment (ESO TRL5).
13096-218
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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MOSAIC is the Muti-Object Spectrograph for the 39m ESO Extremely Large Telescope. The instrument development has recently been reorganized in different channels to be implemented progressively.
The Laboratoire d’Astrophysique de Marseille (LAM) is in charge of the instrument “Assembly, Integration, Test and Verification (AIT/V)” phases. AITV for AO instruments, in laboratory as in the telescope, always represent numerous technical challenges. We already started the preparation and planning for the instrument level AIT activities, from identification of needs, challenges, risks, to defining the optimal AIT strategy.
In this paper, we present the state of this study, discuss a new approach with distributed AIT activities and controlled remotely over different sites. We describe AIT/V scenarios with phased implementation, starting with the Front-End and Visible channels AIT phases. We also show our capacity, experience (several MOS instruments, ELT HARMONI) and expertise to lead the instrument MOSAIC AIT/V activities both in Europe and at the telescope in Chile.
13096-219
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The wavelength dependent refraction of light in the atmosphere causes the chromatic dispersion of a target on the focal plane of an instrument, creating wavelength dependent flux losses across an observing band. In this work we discuss a novel python package, Atmosphyre, which characterises the impact of atmospheric chromatic dispersion on multi-object spectrographs and can be tailored for a custom instrument design. Presented is an application of this analysis for MOSAIC, the ELT’s multi-object-spectrograph, featuring the consequences for survey speed and spectral distortion alongside recommended observation constraints to minimise these impacts.
13096-220
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the conceptual design of the integral field unit (IFU) for Wide Field Optical Spectrograph (WFOS), one of the first-generation instruments on TMT. The IFU is a promising upgrade path of WFOS. The IFU has 4 image slicers with different slice widths of 1.5, 0.75, 0.5 and 0.25 arcsec. The slice length and the number of slices are 20 arcsec and 18 in all slicers. These slicers offer the field sizes of 27, 13.5, 9 and 4.5 × 20 arcsec^2, respectively. This field variation covers sizes of galaxy, circum-galactic medium and inter-galactic medium. In the 0.25-arcsec width mode, the spectral resolution reaches R=13,635 without slit loss. Multilayer dielectric reflective coating with high reflectivity (> 98% at any wavelength) is made on all reflective surfaces, which offers high through put of the IFU (> 80%).
13096-221
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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Wide field optical spectrograph (WFOS) is a multi-slit seeing limited imaging spectrograph at first light for the Thirty meter telescope (TMT). WFOS has a field of view of 8.3’x3.0’ and provides a spectral resolution of R~1500-5000 over 310-1000nm. Since TMT has no dome flat for calibration, WFOS needs an internal calibration system that provides sufficient uniform illumination and mimics the telescope beam. Here, we present a design and performance of a calibration system using a large integrating sphere and an optical projection system that provides uniform and stable illumination across the entire field of view WFOS.
13096-222
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Infrared Imaging Spectrograph (IRIS) is a diffraction-limited instrument designed for the Thirty Meter Telescope (TMT) through international collaboration. IRIS works in tandem with the Narrow-Field Infrared Adaptive Optics System (NFIRAOS) and covers a near-infrared spectral range of 0.84 to 2.4 microns. IRIS and NFIRAOS will be the instruments used to demonstrate first light at TMT. IRIS incorporates a wide-field Imager with a fixed plate scale of 4 milliarcseconds (mas), and an Integral Field Spectrograph (IFS) offering four plate scales that range from 4 mas to 50 mas. In 2021, the major subsystems of IRIS went through final design reviews. This paper provides an update on IRIS design and outlines the plan for its fabrication, integration, and delivery to TMT for first light.
13096-223
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the fabrication and characterization of the optical fibers used in the Large Fiber Array Spectrographic Telescope. The primary goal of the fiber-feed is to maximize the light delivered to the spectrograph while minimizing the system-induced increase in etendue. We are using fused silica fibers with 18 μm cores, which are well-matched to a 1 arcsec seeing-limited image produced by a f/3.5, 0.76m telescope. These fibers are in the ‘few modes’ regime, and exhibit interesting optical properties. We outline the fabrication process for mass manufacturing and assembly of fibers. We also discuss test results regarding focal ratio degradation, throughput, scrambling, and modal behaviors of the fibers.
13096-224
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The mid-infrared (8-14 microns) is invaluable for detecting molecular features in the atmospheres of gas giant and terrestrial exoplanets. The nulling-optimized mid-infrared camera (NOMIC) on the Large Binocular Telescope has a low resolution (R ~200) grism that was previously installed but never characterized. Using a filter in combination with the grism, the infrared window between 7.5 and 14 microns can be captured. We describe initial on sky testing of the LBTI/NOMIC grism mode with adaptive optics. We discuss the impact of observational strategy and precipitable water on the spectral reduction process. Based on these observations we infer achievable exoplanet science on current and future facilities from 8-14 microns.
13096-225
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the preliminary design of the Configurable Slit Unit (CSU) for the Wide Field Optical Spectrometer (WFOS), a planned first light multi-slit spectroscopic instrument for the Thirty Meter Telescope (TMT). The CSU design uses 88 pairs of adjacent motorized bars to create a custom slit mask in the focal plane. The challenge is packaging all the drive components, controllers and encoders within the ~12mm width of a single bar. A 5-bar prototype was built and preliminary results indicate an acceptable repeatability and reconfiguration time. The design of the Acquisition, Guider, and Wavefront Sensor (AGWFS) will also be discussed.
13096-226
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The integrated FE modeling technique allows to combine different FE models, provided by multiple players within a single large model, properly defined “integrated”, useful for the evaluation of particularly relevant aspects of whole system. The development context is the ESO environment for ELT class of Instrumentation. The following paper presents the case study of the MORFEO Calibration Units selector, a very good example of a complex subsystem that integrates other complex subsystems inside the MORFEO MSS (Main Support Structure). This integrated FE modeling work was developed in INAF - Naples Observatory in the ANSYS Workbench software platform. In order to estimate the real behavior of the CU Selector sub-assembly and its related payload it has performed a setting of the integrated analyses. The payloads of the CU Selector are represented by the MCA and the FMCU. They are simulated implementing the FE models provided by MPIA (Max Planck Institute for Astronomy) for MCA and by PF0 WP (INAF - Milano) for FMCU. Also an updated version of CU selector FE model, developed in INAF - Naples, are implemented in the integrated model.
13096-227
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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This paper offers an in-depth study on the structural analyses, performed in INAF – Observatory of Naples, regarding the Interface Joints installed on the ESO Nasmyth Platform of the MORFEO Main Support Structure (MSS). MORFEO is a first light instrument for the ELT (Extremely Large Telescope) that started, since February 2023, its final design phase. This FE model are validated through FEM Analysis approach, utilizing CAD (Autodesk Inventor) and CAE (Ansys Workbench) software. In order to provide an effective survival validation test, it has been simulated the complete earthquake load condition of the MORFEO MSS with its Interface NP Joints mounted below it and its payloads installed on it. All the useful analyses have been developed in detail. Also the operational conditions of the instrument have been checked, simulating the wind effects and the NP induced distortions. In order to have a lighter model for the MORFEO MSS and shorter computational times, simpler FE models than the 3D CAD have been developed. This discretization is a standard approach in the FEA technique and in this paper it is demonstrated that this method still provides accurate results at global level.
13096-228
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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We have designed an Integral Field Unit Spectrometer for the ORCAS Keck Instrument Development II (ORKID II) Instrument. Building on the success of the ORKID instrument (which achieved 15.1 masec FWHM visible spectrum imaging), ORKID II will add Integral Field Spectroscopy to analyze Active Galactic Nuclei (AGN), Supernovae redshift and brightness, and other science observations. Several design options have been explored based on image slicers manufactured by the Canon Corporation’s machining process. Field layouts can include up to three disparate spatial sampling, with a lower limit of 6.7 masec. Spectral resolutions are considered from R 100 to R 10,000. The modular design of the concept allows for configuring the instrument for various observing campaigns.
13096-229
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present a conceptual design of a fiber positioning system for multi-object high-resolution spectroscopy that will require medium multiplexing and be suitable for the upcoming large telescopes. The system incorporates multiple Atmospheric Dispersion Correctors (ADC) for individual targets covering a large field of view (about 2.6m in physical size for the Thirty Meter Telescope (TMT)); an updated design compared to that is discussed in Manjunath et al. (2023). Here, we present a mechanical design concept for the pickoff arms to house the optics and move in a curved focal plane (3m ROC). The tip-tilt mirror allows optimal receipt of non-telecentric input. The mechanical concept allows high targeting efficiency and provides access to the focal volume through four degrees of freedom. The mechanical design and an efficient target allocation algorithm provide 80-100% targeting efficiency for a single exposure. Here, a sequential algorithm for assigning and positioning targets and a Monte Carlo (MC) based algorithm for realistic fields of different target densities to demonstrate the performance.
13096-230
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Large Fiber Array Spectroscopic Telescope (LFAST) will combine 2,640 individual apertures into one telescope array with the collecting area of an ELT (Extremely Large Telescope). The individual apertures are fed into optical fibers, which couple the array to a spectrometer facility. Delivering the starlight in many fibers presents both distinct challenges and opportunities: the virtual slit formed by the fibers is sliced by design; it can be arranged in flexible formats and separated into multiple individual packages. This changes the typical design constraints for high resolution echelle spectrometers for very large telescope apertures. In this contribution we explore the trade-off between different architectures (e.g., one large versus multiple smaller spectrometers), their performance, cost, and development timeline.
13096-406
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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To facilitate the improved sensitivity in the infrared of the next generation extremely large telescopes, improved thermal background correction methods are essential. In this work we investigate the current state-of-the art thermal background correction procedures and propose new strategies to minimize the observed systematic residuals. Using archive data from VLT’s NACO, we show that observations of faint targets are strongly limited by the residual thermal background, which itself correlates strongly to the Adaptive Optics (AO) performance. A model of the systematic residuals in the NACO data is derived allowing a significant reduction of the residuals, especially at worse AO performance.
Session PS3:
Posters - Ground-based Instrumentation in Support of Space Missions
18 June 2024 • 17:30 - 19:00 Japan Standard Time
13096-231
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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This paper discusses the end-to-end mechanical design of the GIRMOS Cryostat which houses the GIRMOS integral field spectrograph (IFS). GIRMOS is an infrared multi-object integral-field spectrograph with a built-in adaptive optics correction mechanism. The overall layout includes four identical channels with each being composed Anamorphic Relay modes, an Image Slicer and an Integral Field Spectrograph all housed within the GIRMOS Cryostat. Additionally, there is a central Imager for doing some parallel imaging which is also housed within this Cryostat. This paper delves into the overall mechanical packaging solution for each of the IFS components and their relative layout within the Cryostat. We also briefly discuss the thermal shielding design implemented along with a comprehensive thermal analysis work done to validate the design decisions. Additionally, we discuss some of the vibration mitigation solutions implemented.
13096-232
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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We discuss the final end-to-end optical design of GIRMOS developed to take advantage of the adaptive optics corrected field at the Gemini North telescope. GIRMOS’s optical design consists of object selection pick-offs, multi-object adaptive optics, and four identical Integral-Field Spectrographs (IFSes), which employ image slicers to arrange the integral field along a slit. The analysis shows the expected performance meets the scientific requirements and the design complies with manufacturability requirements. This paper summarizes the final optical design, tolerance, and pre-testing results of the critical components. GIRMOS will bring high-resolution multiplexed spectroscopic and imaging capability to Gemini North observatory.
13096-233
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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Our team at the Advanced Optical Fabrication Infrastructure (AOFI) has been tasked with the fabrication of the slicer-based IFU for GIRMOS (Gemini InfraRed Multi-Object Spectrograph) which contains 42 250-μm wide slices along with the corresponding pupil and field mirrors. Here we present a test plan and characterization of the GIRMOS SLI system. A comprehensive metrology process is implemented, utilizing equipment such as a Talysurf PGI Freeform profilometer, a ZYGO Verifire HD Fizeau interferometer, a coordinate measuring machine (CMM), a point source microscope (PSM) equipped with a motorized gimbal mount, a scanning electron microscope (SEM), and a custom SLI-M1 test bench. The test plan presented establishes a robust methodology for comprehensive characterization, essential for high precision integral field spectroscopy in astronomical observations.
13096-234
SPIP @TBL: integration and tests of the near-infrared spectrograph unit and synergy with SPIRou@CFHT
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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SPIP is a new-generation near-infrared spectropolarimeter / high-precision velocimeter to be mounted at the 2m Telescope Bernard Lyot (TBL) at Pic du Midi, the French Pyrenean astronomical observatory, in 2024B and mostly copied from SPIRou in operation at the 3.6 Canada-France-Hawaii Telescope (Maunakea, Hawaii) since 2018. Observing in the 0.95-2.5 μm range (YJHK bands), SPIP, like SPIRou, will be dedicated to the detection and characterization of planetary worlds around nearby red dwarfs and to the study of how stellar magnetic fields impact star / planet formation. This paper presents the work performed on integrating and testing the cryogenic spectrograph unit (cooled down at 70K and thermally stabilized at 1mK), benefiting from both the robustness of SPIRou and the design improvements implemented for SPIP.
13096-235
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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SPIP is a new instrument for the 2m Télescope Bernard Lyot (TBL) at Pic du Midi, located in the French Pyrénées. Observing in the 0.95-2.5 µm range (YJHK bands), SPIP at TBL will team with SPIRou at the 3.6m CFHT (Maunakea, Hawaii), aiming together at detecting and characterizing planetary worlds around nearby red dwarfs, and at documenting magnetized star / planet formation. This paper describes the instrument sub-systems integration and validation tests performed in Toulouse (France) with a particular focus on the H4RG detector, failure analysis and mitigation.
13096-236
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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A Python-based spatial heterodyne spectrograph (SHS) model is introduced, generating realistic 2D interferograms for user-selected target stars via an integrated web scraping interface. Demonstrating advantages over traditional remote sensing spectroscopes, the SHS boasts double the resolving power of a grating spectrometer, high throughput akin to a typical FTS instrument, and field-deployable robustness sans scanning components. The model's interferogram processing algorithm ensures flat-fielding, bias-removal, and apodization before employing the Inverse Fourier Transform for source spectra retrieval. Offering optimization results and trade-offs for system parameters, this SHS model aids in designing instruments prioritizing high spectral resolution, especially for applications like isotopic emission line studies. The user-friendly web scraping interface streamlines parameter generation for SHS construction.
13096-237
Light scrambling and focal ratio degradation of thin multimode fibers with different core geometries
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The performance of fiber-fed astronomical spectrographs is highly influenced by the properties of fibers. The near-field and far-field scrambling characteristics have a profound impact on the line spread function (LSF) of the spectra. Focal ratio degradation influences the output beam size, thereby affecting the throughput, as well as the size of the collimator and dispersion elements. While previous research indicated that these properties depend on the shape of the fiber core and showed that non-circular core fibers can yield uniform near-field scrambling, the result is inconclusive for far-field. In this study, we investigate the near-field and far-field scrambling properties, along with the focal ratio degradations, of 50-micron core fibers with different core geometries. We found that in addition to having excellent near-field scrambling, octagonal-core fibers can also produce more uniform far-field output when compared to circular-core fibers.
13096-238
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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The South Africa Near-infrared Doppler instrument (SAND) is a time-stable high-dispersion spectrograph, covering the z- and Y-bands simultaneously (840 - 1090 nm) with the maximum spectral resolution of 60,000. By monitoring radial velocities of stars with the SAND, we aim at search for two types of exoplanets: (1) habitable planets around M-dwarfs and (2) gas-giants with young ages.
We are planning to operate the SAND with multiple telescopes at the South African Astronomical Observatory (SAAO) in Sutherland. Since it is a fiber-fed spectrograph, we can easily change telescope used to collect the starlight by switching the fiber connection. This strategy gives us opportunities of frequent and long-term observations, which provides well phase coverage in radial velocity monitoring and results in non-bias search for exoplanets.
The SAND is currently under assembling, and we will present the detailed status and recent progress.
13096-239
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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MARVEL is a new facility at the Mercator Observatory which comprises an array of four 0.8 metre telescopes, each feeding via fibre link into a single high-resolution spectrograph. The facility will provide dedicated target vetting and follow-up capability to support large exoplanet surveys through radial velocity measurements with precision at the metre-per-second level. The MARVEL spectrograph records five R~90,000 spectra simultaneously in a single exposure across a wavelength range of 380-950 nm. The optical design makes use of simple spherical optics wherever possible, and specifies high-transmission lithography glasses. To confirm that the design performance is within reach, a five-stage optical tolerancing study was undertaken. The resulting tolerances not only directly reveal optical manufacturing requirements, but also inform the optomechanical mounting schemes that will be implemented. The required operational stability of the instrument was calculated in terms of maximum allowable displacement or tilt for each individual component or co-mounted group, translating into requirements on the environmental stability of the instrument, inside and outside the vacuum vessel.
13096-240
18 June 2024 • 17:30 - 19:00 Japan Standard Time
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MARVEL is a new facility at the Mercator Observatory (La Palma) which comprises an array of four 0.8 metre telescopes, each feeding via fibre link into a single high-resolution spectrograph. The facility will provide dedicated target vetting and follow-up capability to support large exoplanet surveys through radial velocity measurements with precision at the metre-per-second level. The observatory site, with four new domes and a standalone stabilised spectrograph building, will soon be complete and ready for hardware installation and commissioning. Here we present an overview of the facility and a status update on several component subsystems: the telescope hardware, control software, and scheduling software; the fibre injection units at each telescope; the optical and mechanical design and tolerances of the spectrograph and vacuum vessel; the calibration system hardware and calibration strategies; and the progress in development of the instrument's data reduction pipeline.
Session PS4:
Posters - Design/prototyping of Instrumentation for Current Observatories
19 June 2024 • 17:30 - 19:00 Japan Standard Time
13096-241
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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4MOST is an upcoming optical, fiber-fed, MOS facility for the ESO VISTA telescope.
1600 fibres go to two Low Resolution Spectrographs which are under the CRAL responsibility. Coverage is 370-950nm at R>4000. Each spectrograph, feeds by 812 fibers at f/3, is composed of a 200mm beam for an off-axis collimator with its Schmidt corrector, three arms with f/1.73 cameras and 6k x 6k 15µm pixel detectors.
This paper describes the assembly, integration and performances achieved at Postdam by the CRAL team for the both Low Resolution Spectrographs. Special emphasis is put on the update of procedures and components to improve performances and meet the top-level requirements.
13096-242
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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BlueMUSE, a blue-optimized, medium spectral resolution, panoramic integral field spectrograph, represents a significant advancement for the Very Large Telescope (VLT). It is designed to build upon and enhance the legacy of the Multi Unit Spectroscopic Explorer (MUSE), a key instrument in VLT's arsenal that has been pivotal in astrophysical research for a decade. This project utilizes the insights from MUSE to refine BlueMUSE, particularly focusing on improving thermal stability aspects. Detailed Finite Element Analysis was employed using ANSYS Workbench to simulate MUSE's thermal, structural, and optical behaviors. The study encompassed a comprehensive model including the Instrument Field Unit , Field Selector Unit, fold mirrors, and lenses. Temperature-related mechanical shifts were integrated into a Zemax optical model to assess impact on system stability. Simulation results were compared with empirical data to validate the model and identify areas for thermal optimization. Additionally, innovative shielding methods to mitigate thermal disturbances were explored, offering potential enhancements for BlueMUSE and influencing the design of future spectroscopic instrument.
13096-243
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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CUBES (Cassegrain U-Band Efficient Spectrograph) is designed to be the most efficient UV spectrograph on an 8-10m class telescope, exploiting the higher telescope efficiency relative to the ESO ELT in ground-based UV wavelengths. The instrument provides wavelength coverage over a range of 300-405nm, with high instrumental efficiency (>37%) and a resolving power of >20,000 (HR) and >6,000 (LR). It will be mounted on the ESO VLT in Paranal. This paper presents the finalised optical design of the system as the project approaches the final design review. The wavelength range, Cassegrain mounting, high-resolving power, and efficiency requirements introduce some unique design challenges and complexities, detailed in the various optical subsystems including: a UV-optimized atmospheric dispersion corrector; high-line density ruled gratings; a dispersion-compensating spectrographic camera design; and an unusual active flexure compensation system.
13096-244
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Gemini High Resolution Optical SpecTrograph (GHOST) is a next generation fiber-fed high-resolution spectrograph which will acquire starlight from the Gemini south telescope via a Cassegrain mounted subsystem and transmit the light through a 25 metre long fiber to a bench mounted spectrograph, residing in the pier lab of the Gemini South telescope.
The need for an ultra-stable system design (for among, other reasons, precision radial velocity determinations) presented several mechanical design challenges, which this presentation discusses. We include the results of trade studies that resulted in changes from the original design concepts, and comparisons and discussion on the reason for the changes.
13096-245
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Gemini Infrared Multi-Object Spectrograph (GIRMOS) will bring high-resolution integral-field spectroscopic and imaging capability to the Gemini North observatory. Designed to work with the Gemini North Adaptive Optics system, it has a multi-object adaptive optics capability that will provide increased resolution and sensitivity for the selected targets. The GIRMOS Calibration System (CAL) is an integral part of the GIRMOS instrument, providing photometric, spectroscopic and metrology calibration. A recent addition to GIRMOS is a field lens assembly (FLA), mechanically integrated with CAL, that provides a telecentric beam and optical shutter. This paper summarizes the final design, mechanical analysis, and optical tolerance analysis of the CAL/FLA subsystem.
13096-246
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Gemini Infrared Multi-Object Spectrograph (GIRMOS) is a powerful next-generation multi-object near-infrared spectrograph incorporating parallel imaging capabilities. In addition to closed-loop Gemini North Adaptive Optics (GNAO) system, each of the four GIRMOS Integral field spectrographs (IFSs) will independently perform additional multi-object AO correction in an open loop. The combined instrument will provide unique scientific capabilities such as simultaneous imaging/spectroscopy modes (for precision spectrophotometry) and interleaved imaging-spectroscopy-imaging modes (for characterizing time-variable sources).
In this paper, we provide a detailed updates and discussion of the mechanical design and analysis of the imager subsystem of the GIRMOS instrument, which is currently in the Critical Design Review (CDR) stage. We place particular emphasis on the design and testing of two cryogenic mechanisms—the filter wheel and the PRS deployment mechanism—along with the innovative design of cryogenic optical mounts.
13096-247
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The High-Resolution Infrared Spectrograph for Exoplanet Characterization (HISPEC) is a new instrument for the W. M. Keck Observatory that enables R~100,000 spectroscopy simultaneously across the y, J, H, and K astronomical bands (0.98-2.5μm). The fiber delivery subsystem of HISPEC is responsible for routing science and calibration light throughout the observatory efficiently. It consists of high-performance single mode fibers (silica for the yJ bands and a custom ZBLAN fiber for the HK bands), a 3-port photonic lantern and mechanical fiber switchers that allow for the reconfiguration of light paths.
Some switchers must make over 800 cycles annually, while maintaining sub-3% coupling losses between fibers with cores sizes of 4.4 microns. To achieve this, extensive testing was conducted, in which throughput and dust accumulation were monitored to determine how these parameters are impacted by switch preparation procedures and ambient environmental conditions and appropriate protocols were developed.
In this paper, we describe the detailed design of the fiber delivery subsystem for HISPEC and outline several innovative solutions and summarize our de-risking activities to date.
13096-248
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The High-Resolution Infrared Spectrograph for Exoplanet Characterization (HISPEC) is a new instrument for the W. M. Keck Observatory that enables R~100,000 spectroscopy simultaneously across the y, J, H, and K astronomical bands (0.98-2.5μm). Here we provide an overview of HISPEC's two stabilized, fiber-fed, cryogenic, diffraction-limited spectrographs: the "blue" arm (yJ), and the "red" arm (HK). The HISPEC optical design is an all-reflective, diffraction-limited echellette spectrometer. The optical designs of the spectrometers are similar: light is injected into a three-mirror anastigmat (TMA) collimator, dispersed and cross-dispersed by Germanium echelle gratings, and finally imaged onto a H4RG-10 detector via a TMA camera relay. The optical bench will be maintained in a CCR-cooled cryostat at 60K +/- 1 mK. We are using ultra-low CTE materials (Invar, Zerodur, Ge) to ensure opto-mechanical stability. The footprint of the two cryostats together will be 36"x92". In this proceeding we describe the optical, mechanical, cryostat, and thermal control design of these spectrographs and how we expect the system to maintain < 30 cm/s stability for the 10+ year expected lifetime of HISPEC
13096-249
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the High-resolution Infrared SPectrograph for Exoplanet Characterization (HISPEC) Calibration Unit (CAL), designed to allow for challenging science cases such as Doppler imaging of exoplanet atmospheres, precision radial velocity, and high-contrast high-resolution spectroscopy of nearby exoplanets. CAL utilizes five near-infrared (NIR) light sources encoded with wavelength information that are coupled into single-mode fiber and can be used synchronously during science observations or asynchronously during daytime calibrations. The go-to wavelength calibration source of HISPEC is a pair of laser frequency combs; one that spans the y- and j-band and the other h- and k-band. These LFCs provide stable, time-independent wavelength information during observation. CAL implements two finesse=40 astro-etalons as secondary relative wavelength calibrators to pair with the LFCs. We use uranium emission lines from a hollow cathode lamp and a series of gas absorption cells to provide absolute calibration from 0.98 µm to 2.46 µm.
13096-250
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The High-Resolution Infrared Spectrograph for Exoplanet Characterization (HISPEC) is a new instrument for the W. M. Keck Observatory that enables R~100,000 spectroscopy simultaneously across the y, J, H, and K astronomical bands (0.98-2.5μm). The front-end instrument steers the adaptive optics corrected beam delivered by Keck to single-mode fibers used to route the light to the spectrographs.
A tracking camera (Teledyne H2RG) is used to monitor the location of the target down to 15th magnitude (H-band) and send commands to a tip/tilt mirror mounted in a pupil plane, which aligns the beam with the fiber in the downstream focal plane. The system will have an atmospheric dispersion corrector to minimize chromatic smearing of the PSF, phase induced amplitude apodization optics to mitigate coupling limitations imposed by the pupil geometry, masks to enable vortex fiber nulling and a K mirror to mitigate the impact of the differential limb coupling effect when observing partially resolved targets.
In this paper we provide an overview of the detailed design of the front-end instrument and elucidate the design choices driven by de-risking exercises.
13096-251
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Liger, an infrared imager and integral field spectrograph for the W.M. Keck Observatory, is a versatile instrument that is designed to take full advantage of the upgraded Keck All-sky Precision Adaptive optics system (KAPA). Supporting a variety of modes of operation in both spatial sampling and spectral resolution required a complex, multi-channel spectrograph optical design. We present an overview of the Liger spectrograph optical design, along with an alignment strategy based on simulations and prototyping for this cryogenic instrument.
13096-252
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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LOFAR2.0 is an upgrade of the Low-Frequency Array, or LOFAR, the world's largest low-frequency radio telescope which will significantly improve its sensitivity and overcome several limitations found during the last 10 years of operation. The core of each LOFAR station are the digital beamformers, called antenna processing subracks (APS), where all antenna signals are digitized and digitally processed to form beams on the sky. The APS has boards ranging from high-speed, high-density digital processing to low-noise RF electronics, to high-current power converters.
The designs of the LOFAR2.0 beamformer are presented, showing how a balanced was struct between performance and cost, while it can be produced in high volumes, and is easy to install and maintained in the field.
The first LOFAR station has been upgraded with new beamformers and the first results will be presented, which demonstrate the new capabilities LOFAR2.0 will have with the new beamformer.
13096-253
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the conceptual design of a room-temperature configurable slit unit (CSU) for the Low-Resolution Imaging Spectrograph 2 (LRIS-2), an upgraded version of a widely used instrument at WMKO. The CSU is a significant enhancement, allowing real-time reconfiguration of slit masks without the need for single-use, machined metal masks. It consists of 72 pairs of motorized bars that can align to form slits, providing flexibility for astronomers in creating various slit shapes and sizes. The CSU will be especially beneficial if Keck receives an adaptive optics upgrade as slits can be adjusted in real time to match the improved seeing.
13096-254
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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LRIS-2 (Low Resolution Imaging Spectrometer) is a planned Cassegrain mounted spectrometer at WM Keck Observatory with on-axis field of view of 5’x10’ in two simultaneous wavelength channels covering 310-1000nm at R~1500 in a single exposure. This instrument will replace its precursor whose optomechanical design and aging mechanisms preclude further improvements in its stability and reliability. The instrument has two science cameras for Red (530-1080nm) and blue (310-650nm) channels, each comprising of six lens elements. This presentation details the design scheme and thermo-structural analysis for the lens mounting strategy. The design features 8 passive radial thermal compensators, addressing differential thermal expansion between Aluminum cell and the lens. A comparative assessment among three material candidates for the compensators resulted in an optimized geometry and hertzian contact stress using finite element analysis (FEA). A prototype was developed to validate the design accuracy and repeatability.
13096-255
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Narrow Field InfraRed Adaptive Optics System (NFIRAOS) in the Thirty Meter Telescope faces challenges with its Visible Natural guide star Wavefront (VNW) sensor's linear stages and encoders. Initial tests revealed deficiencies in magnetic encoders impacting pupil motion calculations at -30°C. Retrofitting with inductive encoders by AMOSIN showed improvement, but fell short. A compensation algorithm was developed to reduce the error to acceptable levels. This paper presents insights from testing different encoders, exploring methods for qualification and troubleshooting, crucial for optimizing NFIRAOS performance in ground-based astronomy.
13096-256
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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In this paper, we present our approach regarding the compensation of defective pixels on the infrared array detector used in the NINJA spectrograph for the Subaru Telescope. The H2RG detector that is planned to use for the instrument has many defective pixels the number of which reaches about 10% of the pixels at the detector's central area. We compensate for defective pixels by a combination of mechanical shifts of the detector along the dispersion direction of the focal plane and post-image processing. The shift mechanism has a maximum stroke of 3 mm with a minimum shift step of 5 pixels or more. This is a similar approach to the concept of dithering in imaging observation. We present the expected performance of this compensation method and the actual mechanical structure fabricated.
13096-257
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Instruments on ground-based telescopes have used optical fibers to feed exoplanet light to spectrographs to enable their characterization. Medium spectral resolution (R~103) strikes a balance between low spectral resolution (CHARIS, R=20-70) and high spectral resolution (REACH, R=105), with the former being spectrally limited and the latter lacking spatial resolution.
The Exo-NINJA project uniquely combines mid-R spectroscopy, high throughput, and spatial resolution, in contrast to CHARIS, which does spectro-imaging, and REACH, which is single-point. By combining SCExAO and NINJA (R=4000 at JHK bands) at the Subaru Telescope using a high-throughput hexagonal multi-mode fiber bundle (hexabundle), Exo-NINJA will provide an end-to-end throughput of 20% compared to the 1.5% obtained with REACH and will aim to characterize exoplanets' atmosphere, detect gas accretion on protoplanets and also detect exoplanets by spectro-astrometry.
We will present a concise overview of Exo-NINJA’s future installation, laboratory tests, and the expected on sky performance.
13096-258
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Subaru PFS is a fiber-fed multiplex system, which enables to acquire approximately 2000 spectra of science objects simultaneously. In order to efficiently share fibers among open-use programs, we develop the PFS Pointing Planner (PPP) to optimize the pointing centers. Its goal is to maximize the completion rate of science programs while keeping a high fiber usage fraction in each pointing. The tool incorporates a flexible weighting scheme that considers factors such as science importance, spatial distribution, and exposure time. We present the simulation results of PPP with mock science programs, and discuss its performance in diverse science cases.
Show Abstract +
While astronomical twilight closes the observing window for optical astronomers, the infrared sky remains dark even through sunrise, allowing IR astronomers to observe through twilight. The Slicer Combined with an Array of Lenslets for Exoplanet Spectroscopy (SCALES) instrument is a 2-5 micron coronagraphic integral field spectrograph scheduled to arrive at Keck in 2025. SCALES has the potential to execute exciting science and support the astronomy community and upcoming NASA missions through a dedicated cadenced twilight observing program. This work presents the scientific motivation and high-level feasibility of two primary science cases, monitoring of Solar System objects and a high-contrast imaging search for exoplanets around bright nearby stars, taking lessons from the existing NIRC2 and OSIRIS Twilight Zone program and considering increases in program scope.
13096-260
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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High-contrast imaging instruments are strongly limited in their performance by wavefront error. Single-point diamond turning allows for high-precision optics to be manufactured for use in astronomical instrumentation, presenting a cheaper and more versatile alternative to conventional glass polishing. This paper, which updates previous work, presents complete measurements of wavefront error power spectral densities for diamond-turned aluminum optics in the Slicer Combined with an Array of Lenslets for Exoplanet Spectroscopy (SCALES) instrument, a 2-5 micron coronagraphic integral field spectrograph under construction for Keck Observatory. Wavefront error measurements for these optics are used to simulate SCALES’ final contrast performance using the POPPY optical simulation package.
13096-261
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The SCALES instrument is a high-contrast imager and integral field spectrograph that operates in the infrared region and is intended to be utilised behind the W.M. Keck Observatory's adaptive optics system. The SCALES integral field spectrograph operates over a broad wavelength range from 2.0 to 5.0 µm. The instrument includes a microlens array-based integral field spectrograph that, when combined with a lenslet to slicer reformatter referred to as "slenslit," allows for low (R = 35 - 250) and moderate (R = 2000 - 6500) spectral resolution spectroscopy. We describe the extensive performance modelling of the final optical design to understand the expected spectral resolution, spectral format, cross talk and PSF profile for SCALES. The analysis used geometric ray tracing of the end to end optical design of SCALES together with physical optics modelling to understand the performance. Combining the optical model together with the scales-sim simulator we are progressing towards developing the data reduction techniques needed for the instrument.
13096-262
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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SCALES, which stands for Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy, is a next-generation instrument planned for the Keck observatory. Primarily, the instrument will do high-contrast imaging and integral field spectroscopy (IFS) of directly imaged exoplanets in a 2.0–5.2 µm wavelength band. The IFS channel of SCALES offers low-resolution (R=35-250) and medium-resolution (R=2500-7000) modes, for the discovery and spectral characterisation of the atmospheres of cold, high-mass exoplanets, and brown-dwarfs with temperatures <600 K. The array of lenslet/slenslit yields multiple spectra in each frame, forming a 3D spectral cube (x, y, λi) of the spatial scene. To facilitate the spectral extraction, a robust calibration system is required to measure the point spread function (PSF) of the IFS at different wavelengths and spatial locations. This calibration system is strategically integrated before the telescope's focus and adoptive optics system, playing a dual role: generating the telescope beam and forming a pupil that aligns with the Keck's pupil before reaching SCALES. In this work, we describe the calibration requirements, design, analysis, and functionality.
13096-263
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The upcoming SCALES instrument for W.M. Keck Observatory will enable coronagraphic imaging and low-/mid-resolution IFS observations over 2-5 micron wavelengths, using two separate HgCdTe Teledyne Imaging H2RG detectors. These detectors are wired for slow-mode readout at a pixel clock rate of ~100kHz, but when operated with a Teledyne Imaging SIDECAR ASIC followed by an AstroBlank/Markury Scientific MACIE controller card, the system can be operated at faster clock rates up to 30MHz, a mode referred to as hybrid fast-slow readout. We perform room-temperature laboratory tests of detector readout to demonstrate feasibility of hybrid readout using a MUX in place of the H2RG, before proceeding into room-temperature and cold tests with the H2RG detector. We test and optimize full-frame data acquisition with pixel clock rates from 5-30 MHz. We present a statistical analysis of the data obtained and discuss the next steps in detector system testing and verification.
13096-264
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present extensive laboratory cryogenic testing and validation results for the linear and rotary stages for SCALES (Slicer Combined with an Array of Lenslets for Exoplanet Spectroscopy). SCALES is a 2-5 micron high-contrast lenslet integral field spectrograph currently undergoing final design and testing for the W. M. Keck Observatory. The linear stage, known as the coronagraph slide, will allow observers the choice of up to 8 coronagraphic focal plane masks. The rotary stage, known as the Lyot wheel, has 15 selectable pupil masks and optics. When deployed behind the Keck Adaptive Optics system, SCALES will be used to detect and characterize a wide variety of exoplanets. To minimize thermal emission, all optical and mechanical components of SCALES are fully cryogenic. Testing was first performed at ambient temperatures and pressures, then validated under vacuum at cryogenic temperatures.
13096-265
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The challenges met in the design of cryogenic instruments for infrared astronomy involve a certain level of uncertainty in the dynamic responses of mechanical components when going from warm to cold. These types of responses include differential contraction of unlike materials, slipping between contact surfaces, and potential for warping of mechanical components depending on stresses inherently present in material. This paper will go over the design and manufacturing principles practiced to mitigate these types of variables that would result in a detriment to performance. The optics, mounts, and alignment features detailed in this paper are to be used for the Slicer Combined with an Array of Lenslets for Exoplanet Spectroscopy (SCALES) instrument, a 2-5 micron coronagraphic integral field spectrograph under construction for Keck Observatory.
13096-266
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy (SCALES) will be a thermal infrared high-contrast integral field spectrograph located at the W.M. Keck Observatory. SCALES will detect and characterize planets currently inaccessible to detailed study by operating at mid-infrared (2-5 µm) wavelengths and leveraging integral-field spectroscopy to distinguish exoplanet radiation from residual starlight. SCALES’ current medium resolution mode (R≈3,500-7,000) will enable investigations of planet accretion processes, though in the future, SCALES will be upgraded with additional higher resolution gratings. We present the designs of custom high-resolution observing modes for SCALES that differentiate accretion properties and geometries from simulated observations of accreting protoplanets. We arrive at these designs by generating a large grid of modeled hydrogen emission line profiles and ray-trace them with SCALES’ end-to-end simulator, scalessim, to produce mock datasets. In this proceeding, we describe the accretion parameter constraining power gained when observing with these specialized accretion-tracing modes over the baseline medium-resolution modes of SCALES.
13096-267
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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SOXS (Son Of X-Shooter) will be the new medium-resolution (R~4500 for 1” slit), high-efficiency, wide-band spectrograph for the ESO NTT at La Silla Observatory, Chile. It will be dedicated to the follow-up of any kind of transient events, ensuring fast time, high efficiency, and availability. It consists of a central structure (common path) that supports two spectrographs optimized for the UV-Visible and a Near-Infrared range. Attached to the common path is the Acquisition and Guiding Camera system (ACS), equipped with a filter wheel that can provide science-grade imaging and moderate high-speed photometry. The ACS was integrated and aligned during the summer months of 2022 and has since been mounted in the NTT’s telescope simulator. This work gives an update on the Acquisition Camera Unit status, describes the Image Quality Tests that were performed, and discusses the ACS Optical Performance.
13096-268
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Son Of X-Shooter (SOXS) will be the specialized facility to observe any transient event with a flexible scheduler at the ESO New Technology Telescope (NTT) at La Silla, Chile. SOXS is a single object spectrograph offering simultaneous spectral coverage in UV-VIS (350-850 nm) and NIR (800-2000 nm) wavelength regimes with an average of R∼4500 for a 1” slit. SOXS also has imaging capabilities in the visible wavelength regime.
Currently, SOXS is being integrated at the INAF-Astronomical Observatory of Padova. Subsystem- and system-level tests and verifications are ongoing to ensure and confirm that every requirement and performance are met. In this paper, we report on the integration and verification of SOXS as the team and the instrument prepare for the Preliminary Acceptance Europe (PAE).
13096-269
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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SOXS will be the single-slit, wide spectral coverage, transient-dedicated dual spectrograph for the ESO NTT at the La Silla Observatory. The instrument is close to its acceptance in Europe and will be reintegrated in Chile in 2024. The verification of the SOXS in Italy is carried out using the Nasmith adaptor simulator provided by ESO and an opto-mechanical setup simulating the telescope beam.
The Telescope Simulator consists of a few optical elements simulating a single source with the right pupil location and variable angular dimension. We present the optical design and characterization of the Telescope Simulator and the alignment strategy when mounted on the NTT-adaptor simulator.
13096-270
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Institute of Astrophysics and Space Sciences is currently developing an instrument to approach the problems imposed by stellar “noise” often associated with the discovery and characterization of exoplanets similar to Earth. Using the Sun as a proxy and with the support of a high resolution spectrograph (ESPRESSO), the Paranal solar ESPRESSO Telescope (PoET) will be able to map the Sun’s surface through simultaneous disk integrated and disk-resolved measurements. To achieve this goal, PoET has the requirement to perform disk resolved observations from 1 to 60 arcseconds. To ensure that the required energy flux for ESPRESSO to operate is always met, an analysis of the radiometric budget for each telescope is required to adjust the frontend for the telescopes. In this work, a summary of the current configuration for PoET and the preliminary assumptions made to build PoET’s radiometric budget will be given.
13096-271
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Cerberus will be a new scientific instrument for the alt-az, 1m-class OARPAF telescope in Northern Italy. Currently, the telescope operates with a CCD camera used for imaging and photometry. One of the objectives of the project is to improve this observing mode with a tip-tilt lens for image stabilization up to 10Hz. Moreover, a long-slit spectroscopy at R ~5900 and an optical fiber échelle spectroscopy at R ~9300 observing modes will be included. Each one of these three "heads'' of Cerberus will be exclusively selected by moving flat 45° mirrors by means of a linear stage placed in a custom interface flange. The flange will replace the existing one, recovering the included field flattener lens, to ensure optical correction of the imaging channel.
We present the already procured COTS hardware, the opto-mechanical design of the interface flange, the results of the Zemax ray tracing, the web-based instrument control software, and the integration schedule.
13096-272
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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A number of millimetre (mm) and sub-millimetre (sub-mm) instruments use half wave plates (HWP) as polarisation modulators, but a thorough account of the non-idealities arising in the HWP is crucial for the analysis of systematic errors. For Cosmic Microwave Background (CMB) experiments, studies propagating the measured spectral performance of a HWP through to scientific results, such as the tensor-to-scalar ratio, r, have not been conducted. Presented in this work are the measured spectral performance of an embedded metal mesh HWP and simulated performance of a 3-plate sapphire Pancharatnam HWP designed for sub-mm studies. These results are propagated through to calculate the bias on r each HWP introduces from it's non-idealities to draw a comparison between the implementation of both types of HWP.
13096-273
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The IBIS 2.0 project upgrades the Interferometric BIdimensional Spectrometer, which was operated at the Dunn Solar Telescope of the National Solar Observatory from 2003 to 2019, for installation at the Teide Observatory. The instrument combines two tunable Fabry-Ṕerot interferometers, narrowband interference filters, a polarimetric unit, fast cameras, and a suitable control for the acquisition of high-resolution spectropolarimetric data of the solar atmosphere in the 580-860 nm spectral range, with short exposures at high cadence under a remote control.
The project underwent several phases. We provide an update on the design progress of the instrument and status of the project, with special emphasis on the challenges arising from the new vertical setup.
13096-274
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We designed an optical system comprising a spectrograph and a telescope (= Dark Matter Quest Spectrograph; DMQS) dedicated to detecting decay photons from dark matter in the infrared region. The infrared high-resolution spectrograph has a maximum spectral resolution of R=30,000 and covers a wavelength range from 0.9 um to 1.35 um. The entrance pupil diameter of the telescope is 80 cm, and the spectrograph is mounted on its Nathmyth focus. The spectrograph employs a long slit of 1.3 arcsec x 6 arcmin to satisfy the required angular resolution and FOV for the science cases proposed by Yin et al. and Bessho et al.
13096-275
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Emission lines originating from chemically induced airglow are both a blessing and a curse for ground-based telescopes. While these lines are commonly used for the fundamental task of wavelength calibration of spectrographs due to their ubiquitous nature, airglow also constitutes the main foreground. Both tasks are complicated by the fact that the lines are highly variable.
Wavelength calibration is often done using a static linelist. However, due to airglow variation, we are calibrating to a moving target, which requires knowing the variability a priori at any resolution. To determine the robustness and variability of the skylines, we have constructed a code to make dynamic linelists at arbitrary resolutions.
The airglow lines are calibration targets due to their strength, but this strength also means that there is a significant foreground signal which needs to be removed. To remove the foreground, valuable observing time is usually dedicated to blank fields of sky. To not waste important observing time on the 8.2m Subaru Telescope, we have constructed a small, auxiliary telescope, The Subaru Night Sky Spectrograph (SuNSS), dedicated to airglow observations, which we introduce.
13096-276
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the new developments about the undergoing upgrade of the FORS2 (FOcal Reducer/low dispersion Spectrograph) instrument at ESO’s Very Large Telescope. This upgrade, dubbed FORS-Up, is now well underway, as a collaboration between ESO and INAF – Astronomical Observatory of Trieste. The FORS-Up new software is developed based on the ELT Instrument Control Software Framework as the upgraded FORS will be the first instrument in operations to use this framework. The new E2V CCD has now been procured and is undergoing testing with the New Generation Controller at ESO. In addition, a new set of filters and of grisms have been developed.
13096-277
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Liger is an imager and integral field spectrograph (IFS) designed to take advantage of the Keck All-sky Precision Adaptive-optics (KAPA) upgrade to the Keck I telescope. The performance of the imager is critical to the whole system as it sequentially feeds the spectrograph and contains essential components such as the pupil wheel, filter wheel, and pupil viewing camera. We present the overall design and analysis of the Liger imager including the fabrication status of each component as well as the full assembly and characterization plan. The imager will be assembled bench-top utilizing a coordinate-measuring machine (CMM) for accurate positioning. To ensure optimal performance, the imager will be characterized in a custom-built test chamber before integration in the full science cryostat. We present the current status of this existing experimental setup. This comprehensive approach ensures the quality and reliability of the Liger imager, enhancing the observational capabilities of Keck Observatory.
13096-278
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Hollow-cathode lamps (HCLs) and gas-discharge lamps (arc laps) remain the principle frequency standards for wavelength calibration of astronomical spectrographs. These sources have been available for decades, are easy to use and integrate, and are more economic in operation than state-of-the art technologies for frequency calibration such as laser-frequency combs. However, the spectral properties of HCLs vary with material purity, production processes, and atomic species, and the available, suitable spectral lines for a given set of instrumentation parameters needs to be experimentally matched with literature line lists.
We present an effort to characterize HCLs of different atomic species and fill gases to evaluate their suitability for medium-to-high resolution astronomical spectrographs and alignment work. Our measurements of a set of HCLs from several suppliers provide line properties, strengths and densities, and wavelength coverage in the VIS and NIR regime. The results can inform optimal wavelength calibration strategies for present and future instruments.
13096-279
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Spectral extraction in lenslet based integral field spectrographs is a challenging problem. Characterising the spectral Point Spread Function (PSF) at the detector using monochromator calibration sequences would be the ideal solution to achieve optimal extraction of the signal especially in instruments like SCALES (Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy) which are built for exoplanet spectroscopy with high contrast. But such a scheme also poses several challenges considering the large total exposure time overheads required for such PSF calibration. An ideal strategy would be using continuum flats to complement the monochromatic PSF calibration set as it can be done as part of day time calibrations. The flats give the PSF profile in the spatial direction and can be used together with the monochromatic data set to implement an extraction strategy that also uses the instrument model and incorporates changes in the PSF profile through different observation runs. We present the simulations of these extraction strategies using the SCALES simulator and using the PSF models from the optical design that has both geometric and physical optics modeling.
13096-280
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The new Integral Field Unit (IFU) for the OSIRIS spectrograph on the 10.4-m Gran Telescopio CANARIAS (GTC), Mirror-slicer Array for Astronomical Transients (MAAT), will see its first light in Autumn 2024. The field is 10" x 7" with 23 slices 0.305" wide, resulting in a spaxel size of 0.254" x 0.305". The wavelength range is 360 nm to 1000 nm. The spectral resolution will be approximately 1.6 times larger than with a standard slit of 0.6" due to the smaller size of the slices. All eleven Volume Phase Holographic Gratings (VPHs) and grisms will be available to provide broad spectral coverage with low to intermediate resolution (R=600 to 4100). The small space envelope, the maximum weight of the mask holder, and the curvature and tilt of the slit created additional design challenges. We will present the relevant aspects of the construction of the MAAT IFU optical bench, mechanical support, and the upgrade of the OSIRIS Mask Charger necessary to host MAAT.
13096-281
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Asgard instrument suite proposed for the ESO’s Very Large Telescope Interferometer (VLTI) brings with it a new generation of instruments for spectroscopy and nulling. Asgard will enable science cases including galactic archaeology (Bifrost) and direct detection of giant exoplanets with the first nulling interferometer in the southern hemisphere (Nott). We present the design and implementation of the Astralis-built Heimdallr, the beam combiner for fringe tracking and stellar interferometry in K band, as well as Solarstein, a novel implementation of a 4 beam telescope simulator for alignment and calibration. This work shows lab results that verify the systems meet requirements and draws general insights from the design and implementation process.
13096-282
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Interferometry and Adaptive Optics (AO) are a highly demanding technology used for astronomical observations, where the complexity of instrument and subsystems maintenance tasks continues to increase. The preparation for interferometry observations under the configuration with the Very Large Telescope (VLT), involves a meticulous examination of all its subsystem’s, resulting in a substantial reduction in available time for daytime maintenance work in different areas. Consequently, it becomes imperative to adopt a new strategy reflected in the Integrate Operations Program, in order to ensure the execution of maintenance task and thereby guarantee its continued reliability and optimal performance
This paper shows different maintenance types and experiences, including the process to schedule some Maintenance activities into the Paranal Schedule.
13096-283
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Spectrograph of the RISTRETTO instrument is now currently being manufactured. RISTETTO is an instrument designed to detect and characterize the reflected light of nearby exoplanets in reflection. It combines high contrast imaging and high resolution spectroscopy to detect the light of exoplanets. The high resolution spectrograph subject of this paper uses the doppler effect to disentangle the planetary signal from the stellar light leaks. In this paper we describe the final design of the spectrograph and report the status of its construction. The RISTRETTO spectrograph has seven diffraction limited spaxels. The spectrograph’s resolution is 130000 in the 620-840 nm band. It is designed in a similar way as HARPS and ESPRESSO, being a warm, thermally controlled spectrograph under vacuum.
13096-284
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The iLocater spectrograph is a new, near-infrared, extreme precision radial velocity (EPRV) instrument under development for the Large Binocular Telescope (LBT) which uses single-mode fibers (SMFs) injected with adaptive optics for illumination. We present an overview of the iLocater calibration system (comprising a custom Fabry-Pérot etalon and a uranium neon hollow-cathode lamp) and the strategies adopted to ensure effective injection of calibration light. This includes custom free-space optomechanics combined with commercially available in-fiber SMF switchers. We present hardware designs and testing which has been completed to ensure performance across the iLocater instrument bandpass.
13096-285
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Liger is an adaptive optics (AO)-fed imager and integral field spectrograph (IFS) designed for W.M. Keck Observatory. This paper will discuss the assembly, integration, and testing (AIT) of the Liger instrument. The project is currently in the first of two-fabrication phases where we are manufacturing, assembling, and testing the complete imager system, the IFS camera TMA, grating turret mechanism, and the IFS re-imaging optics mechanisms. The second fabrication phase will include the final fabrication and assembly of the IFS and science cryostat. An integration phase will follow where the full instrument is assembled and integrated into the science cryostat. Once complete the Liger will be shipped to Hawaii for final assembly, integration, and verification at W.M. Keck Observatory.
13096-286
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the current status of our development of a new near-infrared spectrometer for the InfraRed Survey Facility (IRSF) 1.4-m telescope, located in South Africa. The spectrometer is designed to cover the wavelength range of 1.0-1.6 um with the spectral resolution of 150-200. The spectrometer is also equipped with a near-infrared slit viewer to perform precise spectral monitoring and mapping. We have tentatively completed the development of the instrument by using a commercial InGaAs detector and confirmed its expected performance by test observations with the Kagoshima University 1-m telescope. We now plan to replace the current detector with a new InGaAs detector developed for astronomical observations, which covers the same wavelength range as the current one but has a significantly lower dark current and a larger array format. We plan to mount the spectrometer on the IRSF telescope by early 2025.
13096-287
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The proposed update to 850μm SCUBA-2/POL-2 at JCMT will feature 14544 MKID detectors operated below 100mK, which will map an order of magnitude quicker, and 20 times faster for the polarization.
13096-288
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The VST has been so far one of the best wide-field imagers in the optical bands since the start of operations in 2011. However, in the next years the Vera C. Rubin Observatory will be a game-changer in this field. Hence, the timing is appropriate for specializing the VST with additions that can make it unique in a well-defined scientific niche. The number of telescopes providing polarimetric instrumentation is limited. In the southern hemisphere, the amount of large mirror polarimetric telescopes is small, although they would be specifically needed e.g. to support many science cases of the co-located Cherenkov Telescope Array (CTA). VSTPOL is a project aiming to provide the addition of wide-field polarimetric capabilities to the VST telescope, making it the first large survey telescope for optical polarimetry.
The telescope is equipped with a single instrument, the OmegaCAM wide-field imaging camera operating in
the visible bands with a field of view of 1 deg x 1 deg. The polarimetric mode will be implemented through the insertion of a large polarizer installed on field-corrector optics, which will be exchangeable with the non-polarimetric corrector optics.
13096-289
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The VST (VLT Survey Telescope) is a 2.6m telescope installed in the ESO Observatory of Cerro Paranal, equipped with a wide-field imaging camera operating in the visible band.
One of the goals of the Cherenkov Telescope Array Plus (CTA+) program is to upgrade this ground-based optical facility adding a new polarimetric mode to the VST.
The VSTPOL design aims to replace the actual electro-opto-mechanical system connected to the back side of the primary mirror cell of the telescope with a new system, consisting of two motorized functions: a linear exchanger mechanism to switch between the traditional imaging mode and the new polarimetric mode; a rotating device equipped with a polarimetric filter, replacing the unused ADC functionality, that enables tracking to compensate for the field rotation.
We present the VSTPOL control electronics architecture, based on the new ESO electronics standards.
All the control electronics are hosted in a wall-mountable and properly cooled enclosure installed on-board of the telescope: Commercial Off-The-Shelf (COTS) industrial components represent the core of the system to increase the overall reliability and maintainability.
13096-290
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present the optical and opto-mechanical conceptual design of the Astrophysical Research Consortium Echelle Spectrograph 2 (ARCES2) for the ARC 3.5-m telescope at Apache Point Observatory. The instrument design leverages state of the art concepts and implementations of similar echelle spectrographs. Intended to replace the
venerable but aging ARCES spectrograph, which has been in service for over twenty years, our goal is to design a slit spectrograph with baseline spectral resolution of R = lambda/dlambda = 32,000 and high optical throughput across the 350 -- 1000 nm wavelength range.
13096-291
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We introduce NIGHT (Near-Infrared Gatherer of Helium Transits), a high-efficiency, compact, high-resolution spectrograph. NIGHT's primary mission is to monitor helium envelopes around exoplanets through transits and study variability in their shape. This data will contribute to our understanding of observed exoplanet demographics, for example, the Neptunian desert and radius valley. NIGHT utilizes a novel optical setup with a high-line density, tuned volume phase holographic (VPH) grating in double-pass. With this particular grating, NIGHT reaches a spectral resolution of R=70,000 and a single-pass diffraction efficiency of >85% across its entire bandwidth. These capabilities, only possible because of NIGHT’s specific science case, will facilitate scientific exploration from telescopes with modest apertures, specifically those with diameters below 2 meters. NIGHT is being designed as a visitor instrument and its flexibility and compactness are key to the types of studies we would like to do. This presentation outlines the design and technologies of NIGHT and offers an update on the current status of instrument assembly.
13096-292
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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WALOP (Wide-Area Linear Optical Polarimeter)-South is the first wide-field and survey-capacity polarimeter in the optical wavelengths. It will be mounted on the 1 m SAAO telescope in South Africa to undertake the PASIPHAE sky survey. PASIPHAE program will create the first polarimetric sky map in the optical wavelengths, spanning > 4000 square degrees. In a single exposure, WALOP-South’s innovative design will enable it to measure the linear polarization of all sources in a field of view (FoV) of 35x35 arc-minutes-squared in the SDSS-r filter with 0.1 % accuracy.
As of November 2023, all the individual instrument optical and mechanical subsystems have been assembled and are currently getting tested and integrated. The testing and characterization of the instrument in the lab is expected to be completed by February 2024 and is schedule for commissioning in 2024.
In this talk/paper, we will present (a) the design of the entire instrument and its major subsystems, (b) methodology and results of the lab characterization of the instrument’s performance, and (c) results from the instrument commissioning, if available
13096-293
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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For the fifth Sloan Digital Sky Survey, SDSS-V, we moved one of the two SDSS BOSS spectrographs from Apache Point Observatory in New Mexico to Las Campanas Observatory in Chile for dual-hemisphere coverage. Modifications for connection to a new robotic fiber positioner included replacing the old fiber slit, composed of multiple V-groove blocks, with an innovative monolithic fiber slit consisting of a single precision-machined glass mount holding all 538 fibers. The mount and fibers were polished as a single unit to the curvature required by the spectrograph. Because our existing spare parts inventory would not support two separate locations, and because most parts were no longer manufactured, many subsystems were replaced with new designs.
13096-294
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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This paper presents a miniaturized integrated fiber positioning robots structure scheme for optical survey telescope. The central rotation mechanism and eccentric rotation mechanism of fiber positioner is driven by a DC servo motor with diameter of 4mm. The eccentric shaft motor is offset from the eccentric shaft, and connect with a Oldham coupling. Its spacing can reach 5.4mm, and over 25000 optical fibers can be arranged on a 1-meter diameter focal plane； The device is based on the principle of dual rotation positioning and adopts the method of integrating three positioners into a group. The fiber positioning robot adopts a closed-loop method for positioning. The test results of fiber positioner samples showed that the positioning accuracy less than 0.01mm, meets the requirements of miniaturized intergrated positioner design.
13096-295
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Affordable Multiple Aperture Spectroscopy Explorer (AMASE) is a planned high-resolution spatially-resolved spectroscopy survey of the interstellar medium in the Milky Way and nearby galaxies. The prototype telescope and instrument system, AMASE-P, is under development. We provide an update on the instrument design and report the status of this project. A major design change from the previous report is the use of fused silica etched grating in place of VPH grating. The new gratings would provide a significant improvement in the high-efficiency bandwidth of the spectrograph. For fiber positioning on the pseudo-slit, we adopted a new design for the fiber slit blocks to reduce the risk of damaging the fibers during the fiber insertion process and to strengthen the mechanical property of the blocks. We have also chosen octagonal fibers for more uniform near-field and far-field light outputs to yield more stable line spread function. We report the progress of the project and challenges we encountered.
13096-296
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Cassegrain U-Band Efficient Spectrograph (CUBES) has been designed to provide high instrumental efficiency (> 37%) observations in the near UV (305-400 nm requirement) at a spectral resolving power of R > 20, 000 (offering also a lower-resolution R ∼ 7, 000). With the design focusing on maximizing the instrument throughput (ensuring a Signal to Noise Ratio – SNR– ∼ 20 per spectral resolution element at 313 nm for U ∼ 18.5 mag objects in 1h of observations), it will offer new possibilities in many fields of astrophysics: from solar system to extragalactic. We present the CUBES instrument architecture, interfaces between subsystems and main technical requirements. We describe the optical, mechanical, electrical design of the different subsystems, detailing peculiar instrument functions like the Active Flexure Compensation (AFC) and discussing the main outcomes of the Reliability, Availability and Maintainability (RAM) analyses. Furthermore, we outline the AIT/V concept and the main instrument operations giving an overview of its software ecosystem. Installation at the VLT is currently planned for 2028/2029 and first science operations in late 2029.
13096-297
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We are developing a Fabry-Perot spectrometer for 3D spectroscopic observation to elucidate the physical condition of large scale starforming regions. By varying the interference conditions, images at arbitrary wavelengths can be obtained. Since the observed wavelengths are in the near-infrared, the module must be operated under vacuum and low temperature. The development items are optical element (Fabry-Perot etalon), a drive actuator and ranging system to control the etalon gap, as well as feed-back system to actively control these elements and maintain spectroscopic performance at any operate conditions. The basic performance as a spectrometer will achieve R=6,000 for finesse=60 and order=100.
13096-298
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Simplest Magnetograph is a novel alternative to the standard filter-based magnetograph. The instrument is designed to take broadband measurements of solar polarization. The chosen spectral band covers several photospheric lines with significant g-lande factors. The asymmetry in Stokes profiles results in net polarization, which enables measurements of magnetic fields without resolving individual spectral lines. While the method can be used to measure a full vector magnetic field, in our initial application we concentrated on measurements of the longitudinal magnetic field. This presentation will focus on discussing four (4) main areas; feasibility, design, lab testing and validation, and solar observation measurements.
13096-299
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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VROOMM, a cutting-edge spectrograph for the 1.6-meter telescope at Observatoire du Mont-Mégantic in Quebec, is currently under construction. Specializing in precise radial velocity (RV) measurements for faint stars, it features a 4K photon-counting EMCCD, octagonal fibers, and a double scrambler in a cryostat, achieving a resolution exceeding 80,000. Operating in two modes, VROOMM observes terrestrial planets around bright M dwarfs and conducts photon counting velocimetry for stars as faint as R=19-20, an unexplored area in RV studies. Key applications include confirming brown dwarfs around cool stars and studying stellar dynamics in open clusters. VROOMM's photon counting opens new possibilities for high-precision RV measurements in challenging contexts, showcasing unique contributions to exoplanet system studies.
13096-300
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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High-resolution infrared spectroscopy is a powerful tool for atmospheric science of solar system objects. Aiming at the survey of minor but scientifically significant molecular species and the implementation of a long-period monitoring of atmospheric phenomena in various time scales, we are developing an R=200,000 cross-dispersed echelle spectrograph for K- and L-bands. The spectrograph is so compact and light that it can be mounted at the Cassegrain focus of 1-m class telescopes. The downsizing and the high wavefront accuracy are realized by two germanium immersion gratings manufactured by Canon Inc. (used for both the main and cross dispersers) and an all-reflective optical system made entirely of fine cordierite (CO-720 and CO-220 by KYOCERA Corporation), which is a ceramic with a very low thermal expansion coefficient. This development intends not only scientific studies but also technology demonstrations of the two technologies, which are expected to be widely used in future infrared astronomy.
13096-301
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Differential Image Motion Monitor (DIMM) is the standard instrument used for evaluating the seeing conditions at astronomical observing sites. Previous work has investigated motorising the DIMM to optimise for target selection, but the robotic setup presents a limiting factor and is not always desirable, for example, to support numerous remote optical ground station operation. With this in mind, an untracked, fixed-pointing DIMM has been developed with a user-friendly interface in mind. This aims to enable a network of low-cost robust instruments without needing protective domes to support applications such as astronomical observations or laser communications. The methodology is simulated and developed using Python and then tested with real data taken from observations using instruments placed in La Palma.
13096-302
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We report on the design and development of a precision near-infrared solar spectrometer based on a laser heterodyne radiometer calibrated with an optical frequency comb. We use this comb-calibrated LHR approach to measure the magnetically-sensitive solar Fe I transition near 1565.28 nm. We report new results using two instrument configurations: one that measures the line shape of the target transition at high resolution (R~10^6), and another that uses lock-in detection to stabilize a laser to the target transition, directly tracking its frequency against the comb. In both configurations, our measurements reach sub-50cm/s radial velocity precision within a single day. We operated both instrument configurations near continuously over fall 2023, and we use this long-duration dataset to evaluate systematic uncertainties that can inform future instrument development, with the goal of enabling sensitive studies of solar variability and its effect on precision radial velocity measurements.
13096-303
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Cryoscope is a diffraction-limited 26 cm aperture wide-field NIR telescope that uses optics mounted in a cryogenic environment to minimize background radiation from thermal emission. Different mounting strategies were adopted for each of the optical elements: primary mirror, field flatteners, and meniscus corrector lenses. The opto-mechanical design and mounting schemes are to allow stress-free radial expansion of the optics when transitioning to a cryogenic environment from lab ambient temperatures while providing a factor of safety from other sources of stress such as differential pressure and gravity loads. One of the lens elements provides the vacuum seal to the cryostat which along with a stress-free mounting scheme needs to have permeation characteristics no worse than a typical fluorosilicone O-ring to maintain a low pressure (~1 µTorr) vacuum environment that can withstand the harsh -80C environment for deployment at Dome C in the Antarctic. We present the design, analysis, and prototyping results for the lens mounting schemes in Cryoscope that can be scaled by 4x to 1-m class telescopes.
13096-304
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The High-Resolution Infrared Spectrograph for Exoplanet Characterization (HISPEC) is a new instrument for the W. M. Keck Observatory that enables R~100,000 spectroscopy simultaneously across the y, J, H, and K astronomical bands (0.98-2.5μm). The Front-End Instrument (FEI) steers the adaptive optics corrected beam delivered by Keck to single-mode fibers used to route the light to the spectrographs.
This paper shows the structural (static, dynamic and shock scenarios), thermal (cryogenic H2RG tracking camera and full instrument), and the optomechanical design of the Front-End Instrument (FEI).
13096-305
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Chinese scientists are planning to build an 80 cm aperture near-infrared astronomical telescope at Lenghu, Qinghai Province consisting of one telescope and two terminal devices. The K-band astronomical imaging system serves as one of the primary terminals, specifically designed for observing celestial images within the 2-2.3μm range, with an anticipated capability to discern stars of up to 17th magnitude.
The current K-band astronomical imaging system utilizes MCT detectors, featuring a pixel array of 640x512 and an individual pixel size of 15μm. It employs three detectors arranged in a mosaic configuration, resulting in a focal plane pixel array of 1920x512. To ensure optimal performance of the K-band astronomical imaging system, we implement d Dewar sealing, vacuum maintenance, and thermal acoustic cooling technology to cool the detector to 80K, and optical lenses and components to 150K. Additionally, a low noise power supply design and electronics with low readout noise are employed to ensure minimal dark current and low readout noise for the mosaic infrared camera. In this presentation, we will report the design and its test results of the instrument.
13096-306
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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In the context of the Paranal solar Espresso Telescope (PoET), we are implementing a solar seeing measurement instrument that will be used to measure the seeing during the day in Paranal, Chile where PoET will be installed. In this paper, we will discuss the concept behind the instrument, and present its current phase. We will present the optomechanical, electronics, and software-related components; as well as the first on-sky testing measurements.
13096-307
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present a FPGA control system for CMOS imaging sensors capable of multiple sub-frame readout at a cadence of 20 Hz. The FPGA generates precise timing signals to transfer the electrons from the photodiode to the analog output. The high-resolution successive-approximation-register ADC converts the rolled-out electrons into a series of digital numbers (DNs), and then the FPGA clocks out the serialized DNs into the FPGA block RAM. The FPGA also rearranges the incoming DNs into the desired order before storing them in RAM. We use a FPGA-emulated Microblaze CPU to run Linux as the middleware to send out the image data over Ethernet. Customized Linux drivers were written to move data from video DMA into Linux kernel space and to optimize the ethernet transfer speed via the TCP segmentation offload engine.
13096-308
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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KOSMOS was a long-slit and multi-object spectrograph built for the Kitt Peak National Observatory Mayall 4-meter Telescope. After being decommissioned in 2018, the instrument was acquired by the Astronomical Research Consortium (ARC) to provide high throughput, low resolution spectroscopy for the Apache Point Observatory (APO) 3.5m telescope. The different telescope, user community, and site operation required a hardware and software redesign of the instrument. Renamed KOSMOS II, the instrument was not only revised to integrate with APO's operational environment but also added guiding and internal calibration functionality. Since commissioning, KOSMOS II has proven it is capable of the necessary high-throughput, low-resolution spectroscopy required by the user community of APO's ARC 3.5m telescope.
13096-309
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The ASTRI Mini-Array project, led by the Italian National Institute for Astrophysics (INAF), uses nine dual-mirror Imaging Atmospheric Cherenkov Telescopes to observe high-energy gamma rays. These telescopes are located at the Observatorio del Teide in Spain. The cameras used in these telescopes are based on Silicon Photo Multiplier (SiPM) photodetectors and are an industrial evolution of the system used in the ASTRI-Horn telescope in Sicily since 2016. We present the main features, the development phases and the results of the first camera, which is being installed on the first of the nine telescopes.
13096-310
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Multi-Aperture Spectroscopic Telescope (MAST) is a new telescope array with a novel design, being constructed at the Weizmann Astrophysical Observatory in Israel. It comprises twenty 60 cm telescopes, collectively providing the light-gathering power of a single 2.7 m telescope. MAST features two fiber-fed spectrographs with low and high resolutions, covering the optical domain. To remove instrument signatures and calibrate the wavelength, a calibration unit utilizing quartz-tungsten-halogen (QTH) and ThAr lamps to generate arc and flat spectra will be employed. The lamp outputs are homogenized and distributed into five identical fiber outlets for the spectrographs via a series of beamsplitters. This presentation outlines the opto-mechanical design of the calibration unit and discusses the development plan for the subsystem.
13096-311
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Transmission spectroscopy is a powerful observing technique to probe the atmospheric spectrum of an exoplanet that transits its host star. Low resolution transmission spectroscopy can probe both spectral features and the continuum of a planet's atmosphere, but is difficult to do from the ground due to Earth's atmosphere. Here we present HIRAX, a ground-based instrument capable of imaging a system simultaneously in multiple narrowband filters to perform transmission spectroscopy in three 3Å wide bands. HIRAX uses self-referenced bandpasses and a simple imaging design to reduce systematic effects related to Earth's atmosphere and probe an exoplanet transmission spectrum at a few stable wavelengths. HIRAX has been designed for characterizing the sodium doublet (5889.9Å and 5895.9Å) in hot Jupiter atmospheres using the Hale telescope at Palomar Observatory. Here we present the motivation for HIRAX, detail its optical and mechanical design, and present several requirements we imposed on HIRAX in order for it to achieve a photometric precision near the photon limit. We also detail the status of HIRAX and future observing plans.
13096-312
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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VIRUS2 is a new NSF-funded fiber-fed multiplexed integral field spectrograph consisting of 6 units, each with 4 spectral channels, providing large on-sky area coverage coupled with broad spectral coverage (370-930 nm at R~2000). On the McDonald Observatory 2.7 m Harlan J Smith Telescope, VIRUS2 will cover a 1.7 by 1.3 = 2.3 sq. arcmin. field of view, with full fill-factor. The optical fiber based integral field units employ several novel features and fabrication techniques. The pseudoslit at the spectrograph end of the integral field unit form a compound curvature which presented new challenges over previously built instruments. Additionally, the input end of the fiber bundle constrains the fibers in a glass hole block and is immersed in a stack of microlens arrays. This paper details the integration and alignment techniques used in constructing these integral field units.
13096-313
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We introduce MOSES, the new High-Resolution Echelle Spectrograph designated for the 1.2m MONET telescope at McDonald Observatory, Texas, USA. The science drivers are radial velocity experiments and activity monitoring in sun-like stars. Set for installation in the final quarter of 2025, MOSES features a white pupil design and aims for a spectral resolution greater than 80,000 over the 380-680 nm wavelength range. It incorporates a pixel sampling rate of 3.5 and uses two fibers to facilitate a simultaneous calibration mode. Encased within a vacuum vessel and operating in a temperature-stabilized environment, MOSES is expected to achieve a radial velocity precision below 2 m/s, aided by a Fabry-Pérot etalon calibration system. This paper outlines the implementation of the fiber injection unit, the optical layout of the spectrograph, and the present status of the various subsystems under development.
13096-314
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The original Fabry-Pérot (FP) units of the CARMENES spectrograph at the Calar Alto 3.5m telescope have been essential to track and remove instrumental drift while also improving the wavelength solution provided by the hollow cathode lamps. In this paper we present the second-generation FP unit that is set to begin operation at Calar Alto in early 2024.
It features drastically improved temperature stabilization, better temperature monitoring, and enhanced optomechanics and optics. All these improvements are the result of a number of iterations on the overall design, which have been rigorously tested in our laboratory.
We have recently demonstrated that our similarly constructed laboratory FP unit achieved a radial velocity stability of approximately 10 cm/s over 90 hours, and now we compare the new CARMENES unit's performance to this benchmark.
13096-315
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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Tenerife Microwave Spectrometer (TMS) is a ground-based experiment by the Instituto de Astrofísica de Canarias (IAC) placed in the Observatorio del Teide (Tenerife, Spain). It operates in a temperature range of 4-10 K. Due its architecture, the instrument presents an asymmetric heat load shape which collides with the tight thermal requirements, which consists of a thermal gradient symmetry of ±100 mK and a thermal stability of ±1 mK/h.
The conceptual design of the cold structure and the followed workflow performed to fulfil these thermal requirements are described.
13096-316
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present an innovative design for a new full disc solar spectropolarimeter. The instrument is part of the new container based Tautenburg Solar Laboratory (TauSoL), that is currently under construction and commissioning on site of the Thüringer Landessternwarte Tautenburg (TLS), Germany. The initial design approach is to use a single Fabry-Pérot etalon with 150mm clear aperture that is placed at the aperture of the solar telescope inside the container-lab. In our paper we present the current status of TauSoL and the detailed design of the light feed and the initial multi-line solar spectropolarimeter.
13096-317
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The main goal of the third iteration of the High Accuracy Radial velocity Planet Searcher (HARPS3) is to search
for Earth-twin planets over a ten-year programme. As part of this search, spectropolarimetric observations have
been envisioned foreseeing the need for new ways to reducing stellar activity jitter which obscures the 10 cm/sec
radial velocity signal of such planets. HARPS3 has thus been designed with an insertable polarimetric sub-
unit. This sub-unit consists of two superachromatic polymer retarders, one quarter-wave and one half-wave, to
separately detect all Stokes parameters of a target, as well as a novel wire-grid polarimetric beam splitter to
separate the parallel polarimetric beams by 30 mm to feed the science fibers. In this paper we report on the
realization, performance, and possible upgrades of the currently installed polarimetric sub-unit for the Cassegrain
Adaptor Unit of the HARPS3 spectrograph and discuss the observation schedule of polarimetric observations for
the Terra Hunting Experiment and the possible impacts of polarimetric observations on mitigating stellar radial
velocity jitter.
13096-319
19 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
In order to derive solar magnetic fields, we are developing a 2D spectropolarimeter working in near infrared wavelength range. A voltage-tunable LiNbO3 etalon filtergraph is used as a 2D spectrometer. A rotating waveplate for modulating the polarization is used, which has a nearly constant retardation of about 127 degs over wide wavelength range. The filtergraph consists of two etalons of 0.9 mm and 1.2 mm thick, optimized in an ordinary ray transmission for both He I 1083 nm and magnetic sensitive Fe I 1564 nm lines when used in tandem configuration. The etalons are Y-cut LiNbO3 wafers coated with reflective and conductive (ITO) layers. A linear polarizer between the rotating retarder and the filtergraph works for a polarization analyzer and a selection of the ordinary ray transmission. We carried out polarization observations of solar active regions in several wavelength points in He I 1083 nm line with a high speed IR camera at Hida observatory, Kyoto University. Some observational results together with the instrumental properties and a method of data reduction are presented.
13096-320
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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We report on the design of 2ES (Second Earth Initiative Spectrograph): a new fiber-fed, high-resolution, high-precision radial velocity Echelle spectrograph for the 2.2m ESO/MPG telescope in Chile, which will cover the visible wavelength range (~370-850 nm) with a resolution of ~120,000. 2ES will be dedicated to a > 5-year observing program with access to the majority (2/3) of the telescope time with the goal of discovering temperate terrestrial Earth-mass planets in the habitable zone around the bright solar-type stars. To achieve this goal, 2ES aims for ultra-high instrumental radial-velocity precision and an observing strategy that involves high-cadence observation of the brightest Sun-like stars in the Southern Hemisphere. Here, we present an overview of the project, its observation strategy, the optical design as well as the opto-mechanical concepts and calibration strategies to achieve the required instrument stability.
13096-321
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Magellan InfraRed Multi-Object Spectrograph (MIRMOS) is a planned next generation multi-object and integral field spectrograph for the 6.5m Magellan telescopes at Las Campanas Observatory in Chile. MIRMOS will perform R~3700 spectroscopy over a simultaneous wavelength range of 0.886 - 2.404um (Y,J,H,K bands) in addition to imaging over the range of 0.7 - 0.886um. The integral field mode of operation for MIRMOS will be achieved via an image slicer style integral field unit (IFU) located on a linear stage to facilitate movement into the beam during use or storage while operating in multi-object mode. The IFU will provide a ~20”x26” field of view (FoV) made up of 0.84”x26” slices. This will be the largest FoV IFS operating at these wavelengths from either the ground or space. In order to achieve the desired image quality and FoV, our slicer design makes use of novel freeform surfaces for the pupil mirrors, which require the use of high precision multi-axis diamond milling to manufacture. We present here the optical design and predicted performance of the MIRMOS IFU along with a conceptual design for the opto-mechanical system.
Show Abstract +
Keck Observatory’s FOBOS spectrograph will be a flagship instrument for Keck in the 2030s. Deploying 1800 fibers feeding three bench-mounted spectrographs, FOBOS will obtain deep sensitivity over a wavelength range from 310-1000 nm at a spectral resolution of R~3500. The FOBOS focal plane will offer unique flexibility for observers who will be able to choose and mix modes that deploy single-fiber apertures, multiple IFUs, and a large, monolithic IFU. FOBOS is baselining Starbugs fiber positioners because of their large, overlapping patrol fields. A zonal positioning system with an array of high-throughput fiber switches may present an alternative means to achieve the desired flexibility at the focal plane. In order to prototype and test these concepts, we have built a Focal Plane Demonstrator for FOBOS which supplies source light with a mock Keck pupil at f/15. Here we report on initial testing with the demonstrator, with a focus on lenslet coupling performance, throughput, and ouput beam quality (focal ratio degradation).
13096-404
Development and Initial Testing of a Fiber-fed Fourier Transform Spectrograph for Solar Spectroscopy
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Fourier Transform Spectrograph (FTS) stands as a powerful tool for astronomers in characterizing the composition of celestial bodies through their emitted light. We introduce the development and initial performance evaluation of a fiber-fed FTS, specifically tailored for solar observations within the 600-1000 nm wavelength range. To improve measurement precision, a stabilized He-Ne laser is integrated as a metrology wavelength source. This setup generates a monochromatic interferogram in parallel with the scientific interferogram, allowing for adaptive correction of the instrument's non-linear scan characteristics that affect the phase information of the scientific interferogram. For wavelength calibration, well-defined oxygen (O2) bands are employed as a reference. The comparison of the solar spectrum measured with our system against a simulated model showed a good agreement, affirming the system's efficacy. Additionally, wavelength calibration using O2 bands in the telluric region is discussed, offering insights into the system's repeatability. The analysis of the Fe-I absorption line within these bands further enabled us to determine the Sun's rotational velocity.
13096-405
19 June 2024 • 17:30 - 19:00 Japan Standard Time
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In fiber-based spectrography within telescopes, a prevailing limitation has been the necessity to align the fiber diameter with the telescope’s seeing conditions, often characterized by the Full Width at Half Maximum (FWHM) of the point spread function. This alignment constraint captures around 50 % of the incoming flux from any point source. Furthermore, the challenge is compounded when high-resolution spectrography is in play, as it often demands a minute slit width, further exacerbating flux loss. The essence of this paper lies in a comprehensive exploration, accomplished through theoretical simulations, of strategies aimed at enhancing the coupling efficiency of high-resolution spectrographs. The primary objective is to bolster the flux capture without compromising the critical aspect of spectral resolution. This research endeavors to unlock the potential for more effective utilization of high-resolution spectrographs to study celestial objects.
Session PS5:
Posters - Rapid-response instruments
20 June 2024 • 17:30 - 19:00 Japan Standard Time
13096-323
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present a status update on SCORPIO, the next facility instrument for the Gemini South telescope at Cerro Pachon, Chile. SCORPIO is now in advanced Assembly, Integration and Verification phase in Madrid, in anticipation of shipment to Chile by mid-2025.
13096-324
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The rate of transient discoveries and alerts is poised to increase exponentially in the coming years, driven by data-intensive surveys such as the LSST. In anticipation of this influx of alerts, the South African Astronomical Observatory (SAAO) has initiated the "Intelligent Observatory'' (IO) project. In this presentation, we provide a brief overview of the IO project but mainly highlighting the instruments and telescopes, both new and existing, that have been equipped with full autonomous observing capabilities to advance one of the IO project's core goals of rapid follow-up response to transient alerts. Of particular focus is Mookodi, a newly installed and commissioned low-resolution spectrograph with a multi-filter imaging mode, mounted on the 1-meter Lesedi telescope. Furthermore, we will showcase the integration of these telescopes and instruments into the recently open-sourced Observatory Control System (OCS) developed by the Las Cumbres Observatory (LCO), which the SAAO has adopted for the IO project. We finish off by showing some use cases demonstrating the rapid-response capabilities.
13096-325
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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CFHT has developed an astrometric camera to reduce the time-to-target for CFHT’s narrow FOV fiber spectrographs, ESPaDOnS and SPIRou. Both instruments have small pierced mirrors with FOVs of approximately 70 arcseconds making astrometric calibration crucial to accurately place the science target on the pierced mirror. While a two-dimensional 3rd-order polynomial fit pointing model that relates the astrometric camera field to that of the telescope has been implemented, high model residuals pose challenges in placing the correct target on the fiber. The unique nature of the astrometric camera pointing model, comparing rotations between two image fields, is a departure from the previous pointing models. This study aims to address the issue by identifying sources of residuals in the existing E(3)-fitting model and implementing a fitting method optimized for angular deviations in SO(3). Differing fitting methods will be performed on the same dataset and their resulting residuals will be presented. The outcome of this study is expected to improve the accuracy of the astrometric camera pointing model, reducing the time-to-target for the ESPaDOnS and SPIRou instruments.
13096-326
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The New Robotic Telescope (NRT) will be the world’s largest fully robotic optical telescope; and with an ambitious time-to-target requirement of 30 seconds it needs a fast-reacting instrument suite to match. The spectrograph for the NRT will be based on LT-SPRAT; the spectrograph on the Liverpool Telescope (LT), but without moving parts. LT’s photometric capabilities provide a good opportunity for a dual facility where the LT is used for imaging and the NRT is used for spectroscopy.
The NRT spectrograph will be responsible for providing much of the classification data for new transient objects, which is one of the main scientific goals of the facility. It will cover a wavelength range of 3750 – 7500Å and have a spectral resolution R~400.
Session PS6:
Posters - Design/Prototyping of Instrumentation for Current Observatories
20 June 2024 • 17:30 - 19:00 Japan Standard Time
13096-327
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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We have developed a novel fibre feed for the DOT-HRS (Devasthal Optical Telescope High-Resolution Spectrograph) instrument to enable precise Doppler radial velocity observations in the wavelength range of 380-850 nm. The fibre feed offers high-resolution (HR) and high-efficiency (HE) observing modes using a combination of CeramOptec Optran WF circular and non-circular fibres. In this paper we present the design of the fibre system, including Cassegrain unit, mirror-based image slicer, wavelength calibration unit, and the spectrograph slit.
13096-328
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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DOT-HRS is a high resolution echelle spectrograph to enable precise Doppler radial velocity observations at the Devasthal Optical Telescope (DOT) in India. The spectrograph uses a single-arm white pupil echelle design that operates in the wavelength range of 380-850 nm. The optical bench is surrounded by a vacuum vessel and temperature stabilised to 1 mK or better. In this paper we present the opto-mechanical design of the spectrograph and a detailed thermal analysis to understand the impact of different leakage paths, the impact of ambient temperature variations, and to determine the overall control system strategy.
13096-329
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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TIFR-Mumbai and ARIES-Nainital are jointly developing a Multi-Object Optical to Near Infrared Spectrograph (TA MOONS) for conducting the world’s largest optical to near infrared spectroscopic survey for young stellar objects (YSOs). This instrument will be unique in the world due to its capability to simultaneously obtain 380 nm to 2500 nm spectra, at a resolution of R~2500. It is also capable of obtaining spectra of 8 sources in the 12 arc-min diameter field of view of 3.6m Devasthal Optical Telescope (DOT) in India. These 8-sources within the FoV is acquired by moving 8 pickup arms (r,θ) in the front optics of the spectrograph. In my talk, I will present the opto-mechanical design around the optics to fulfil the design tolerance requirements and a prototype of the front optics called “Pick-up arm assembly” and achieved tolerance.
13096-330
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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We design a simulation and test system To test the Front-End electronics board (FEB) of the CCD detector system of Wide Field Survey Telescope (WFST). There are three types of CCDs used in the CCD detector System of WFST: CCD290, CCD250, and CCD47-20. The CCD290 is driven by FEB-SCI, and the CCD250 and CCD47-20 are driven by FEB-WG. For fast and accurate test, the CCD simulation and test system can provide 20 channels of clock detection, 16 channels of bias and 16 channels of bias noise detection. In addition, the simulation and test system can also provide a simulated CCD waveform output for testing the performance of video waveform sampling circuits of a FEB. The CCD waveform output module consists of a digital waveform output module and an analog waveform output module, which can be selected depending on specific requirements. This simulation and test system has been used to test the FEB performance in the Wide Field Survey Telescope.
13096-331
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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In the closed-loop fiber positioning control mode of the LAMOST, there are stringent requirements for time efficiency. However, due to the impact of image resolution and image transmission required for fiber optic positioning, the current time efficiency of closed-loop control still fails to meet the requirements. This paper proposes an improved high-precision fiber position recognition method and ports it to the edge fiber unit detection module on the FPGA, which can greatly save spots calculation time. The paper uses Vivado HLS to port the algorithm to the FPGA, and by assigning labels to the spots, the centroid coordinates of the spots can be obtained by scanning the image once. The results show that the new hardware architecture can effectively shorten the data transmission time, and the improved centroid method is more suitable for the FPGA. This algorithm has been preliminarily applied in the LAMOST closed-loop detection system after experimental verification.
13096-332
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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TIFR and ARIES team are jointly developing a multi-object optical to near infrared spectrometer, with the primary science goal to conduct world’s largest optical to near-infrared spectroscopic survey of YSO’s. The spectrometer is capable to observe 8-objects simultaneously located within the large sky FOV of 12 arc-min diameter, from 380 nm in optical to 2500 nm in near-IR. The front optics uses the eight mirror based pick-up arm system to acquire the light from the large focal plane and forms a compact slit at the entrance of a two arm cross-dispersed spectrometer. Talk will present the optical design of the front optics and the design of this spectrometer.
13096-333
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The wavelength range around 1.4 μm is highly opaque on the ground due to water vapor absorption in the Earth's atmosphere. However, at Dome A, Antarctica, where the precipitable water vapor (PWV) is exceptionally low, this range becomes nearly transparent. It allows for accurate observation of spectral features, such as water absorption in exoplanets and late-type stars. The W band filter, introduced by Allers et al. (2020), has been successfully implemented to differentiate these stars from early-type reddened background stars. In this study, we aim to tailor the W-band filter design specifically for Dome A, Antarctica, to achieve enhanced accuracy and efficiency. By adjusting the wavelength center and width, we will determine the optimized configuration for determining spectral types, taking into account the typical atmospheric transmission at Dome A. We will also investigate the impact of PWV fluctuations on the filter's performance.
13096-334
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Studying the atmospheres of exoplanets is a critical and rapid way to learn more about worlds outside our solar system. Higher resolution capabilities are necessary to distinguish overlapping absorption patterns from different molecules, especially for ground-based observations where an ideal R ~ 100,000 is desired. The structural simplicity and compact dimensions of Virtually Imaged Phased Array (VIPA) render it highly suitable as the primary dispersing element in ultra-high resolution narrow-band spectrometers. This work aims to enhance the throughput of a VIPA spectrograph by using a Volume Phase Holographic Grating as a cross-disperser in the VIPA Instrument for Oxygen Loaded Atmospheres (VIOLA). This fiber-fed VIPA Instrument targets a spectral range of 700-800 nm, coupling with a replaceable input optics module for f/ratio adjustments when transitioning between different telescopes. Using high-performance, commercially accessible optical components facilitates swift and efficient implementation. This work delves into optical design, resulting image quality and prospects for VIOLA in advancing high-resolution spectroscopy for the study of exoplanet atmospheres.
13096-335
20 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We present the updated optomechanical design and as-built laboratory performance for HighSpec, a high-resolution R=20,000 spectrograph designed for the Multi-Aperture-Spectroscopic Telescope (MAST). HighSpec offers three narrow bandpasses (10-17 Å) observing modes centered at the Ca II H&K, Mg b, and Hα lines. Each mode is supported by a highly optimized ion-etched grating, contributing to an end-to-end exceptional peak efficiency of ≳ 55%.
The instrument has been optimized for several studies, mainly in the field of exoplanetary and stellar science, including a systematic survey of flaring M-dwarfs hosting potentially habitable planetary systems, Doppler tomography studies of exoplanet obliquity, and dynamical studies of the local population of short-period double white dwarfs.
Its integration with MAST, an array of 20 custom-designed telescopes that can function as a singular large unit (equivalent to a 2.7m telescope) or multiplexing over the entire sky, provides unique adaptability for extensive and effective spectroscopic campaigns.
Currently in its final assembly and testing stages, HighSpec's on-sky commissioning is scheduled for the summer of 2024.
13096-336
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The AZT24 telescope at Campo Imperatore observatory, at an elevation of 2200 m a.s.l., has been acquiring NIR images since 1996. It will now be upgraded with a new IR imager, based on an InGaAs detector, assisted by a devoted Tip-Tilt (TT) corrector.
The overall project is presented in this paper, with emphasis on the opto-mechanical layout, the camera and the performance simulations. A set of science cases is reported, ranging from extragalactic Astronomy to stellar Astrophysics and Solar System studies. The system can also act as a testbench for new ideas on AO and data processing techniques.
13096-337
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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MAVIS is a Multi-Conjugate Adaptive Optics for the UT4 of VLT designed to deliver a corrected FoV to a spectrograph, an imager, and a visiting instrument. An optical bench, kinematically mounted on the overall main structure (OMS) is used to support the post focal relay optics, which include the ADC, a K-mirror, the DMs, the calibration, and the selectors. Said bench also rigidly supports the LGS module, the NGS module and the imager.
The design and analysis of the steel bench is presented together with the design, analysis, and prototyping of the optomechanical elements. Particular attention is given to the evolution of the derotation system design (K-mirror), which has been strongly improved, and to its prototyping.
13096-338
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The MCAO Assisted Visible Imager and Spectrograph (MAVIS) is a new high-resolution instrument operating in the visible band (370-935 nm) that will be installed at the Nasmyth A focus of the ESO VLT UT4.
The system is characterized by an Adaptive Optics Module (AOM), a Calibration Unit, an Imager and an IFU Spectrograph. The project recently passed the Preliminary Design Review and is currently in the Final Design phase which is expected to end in December 2024, according to the current schedule.
In this paper we present the improvements in the AOM control electronics architecture, focusing on the new layout, the interfaces with the AO sub-modules and the prototyping activities carried out during this phase.
13096-339
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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MAVIS (MCAO-Assisted Visible Imager and Spectrograph), planned for the VLT Adaptive Optics Facility, represents an innovative step in Multi-conjugate Adaptive Optics (MCAO) systems, particularly in its operation at visible wavelengths and anticipated contributions to the field of astronomical astrometry. Recognizing the crucial role of high-precision astrometry in realizing science goals such as studying the dynamics of dense starfields, this study focuses on the challenges of advancing astrometry with MAVIS to its limits as well as further enhancing it by incorporating telemetry data as part of the astrometric analysis. We employ MAVISSIM, PASSATA and TipTop to simulate both MAVIS imaging performance and telemetry data. Photometry analyses are conducted using the SuperSTAR and DAOPHOT platforms, integrated into a specifically designed pipeline for astrometric analysis in MCAO settings. Combining these platforms, our research aims to elucidate the impact of utilizing telemetry data on improving astrometric precision, potentially establishing new methods for ground-based AO-assisted astrometric analysis.
13096-340
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present a concept design for a next generation low resolution, wide-field, optical imaging spectrometer
intended to continue the legacy of LRIS as the premier workhorse optical spectrometer on the Keck 1 telescope,
which we notionally call LRIS-2. The original LRIS continues to be used an average of more than 100 nights
per year while maintaining a remarkably high publication rate, neither of which shows any signs of diminishing
with time. Nevertheless, LRIS was commissioned ~30 years ago, and its opto-mechanical design and aging
mechanisms preclude further improvements in its stability and reliability. This paper presents the conceptual design of a state-of-the-art instrument combining the core capabilities and scientific versatility of LRIS with substantial
improvements in throughput, image quality, stability, and on-sky efficiency. In this paper, we present a baseline
concept for a versatile imaging spectrometer with an on-axis field of view of 10' × 5' in two simultaneous
wavelength channels that together cover 3100-10,300 Å at R∼1500 in a single exposure, with a multiplex
factor up to 70.
13096-341
20 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The KPEC spectrograph has been designed and developed by the AAO for the KMTNet-SSO telescope. The design is an evolution of the optomechanical experience gained at the AAO though the development of multiple spectrographs
13096-342
20 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
The HISPEC instrument under development for Keck Observatory is designed to support multiple modes of infrared exoplanet detection and characterization, including via host star radial velocity measurement, using single-mode fiber-fed echelle spectroscopy. As such, the backend spectrometers are designed to achieve an internal velocity precision of 30 cm/s. The diffraction-limited spectrometers are designed to meet thermo-mechanical stability goals and requirements. While the design of each cryostat features common strategies for cryogenic stability, including a vacuum shield, multi-layer insulation, a cold radiation shield and additional baffling, and thermal coupling to the closed-cycle refrigerator, there are several aspects of the design that have been driven by thermal stability requirements. In this presentation we will review the various levels of thermal modeling used to inform the design, as well as the resulting passive and active design features, such as copper buses for heat transport, thermal ballast, and multi-input/multi-output active thermal control. We will also present the results of verification analyses that suggest performance requirements will be met.
13096-343
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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ÉBANO will be an integral-field spectrograph for the 84 cm telescope at the National Astronomical Observatory in Sierra San Pedro Martir (Mexico). The design is based on an angular-scanning technique using a narrow-band filter, changing gradually the angle of incidence of the beam thus shifting the transmition wavelength of the filter. We plan to do a complete cartography of the Andromeda galaxy (M31) with a mosaic of about 250 images of 6.5x6.5 arcseconds FoV each, scanning the spectral lines [SII]6716,31, HeI, Ha and [NII]6548,84. We show that this can be done using a single filter centered at 6770 Angstrom and an angular scan of 35 degrees.
13096-344
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The High-Resolution Infrared Spectrograph for Exoplanet Characterization (HISPEC) is a new instrument for the W. M. Keck Observatory that enables R~100,000 spectroscopy simultaneously across the y, J, H, and K astronomical bands (0.98-2.5μm). This will be accomplished by splitting the light into a "blue" arm (BSPEC; yJ) and "red" arm (RSPEC; HK). The optical prescription of BSPEC and RSPEC are similar all-reflective designs: light is injected into the spectrograph via a fiber-optic cable, relayed through a three-mirror anastigmat (TMA) collimator, dispersed and cross-dispersed by Ge echelle gratings, and imaged via a TMA camera relay onto a H4RG-10 detector. We optimize the focal length of the TMA collimators to match the numerical apertures of the fibers. Of the two systems the RSPEC fiber produces a faster divergence and therefore requires a shorter focal length. Maintaining high wavefront quality over a larger field of view is more difficult for shorter focal lengths, hence we prototype the RSPEC collimator as a de-risking exercise. In this proceeding we describe the final optical, opto-mechanical, and thermal designs of the RSPEC collimator and the prototype performance.
13096-345
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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FALCON is a conceptual, multi-purpose, facility instrument for the Magellan Baade telescope designed to enable astronomical research across many disciplines. The instrument has three modes of operation: low resolution spectroscopy (R = 1560 – 5860), high resolution spectroscopy (R = 3110 – 11650), and imaging, all of which are corrected for seeing-limited performance from 3300 Å to 10500 Å. The camera optics are constrained to be under 200 mm in diameter by splitting the field of view in half and reflecting each half into an identical spectrograph. The design achieves high spectral throughput (> 60%) by further splitting the field into four spectral channels, for a total of eight spectral channels and a 23 x 23 arc-minute field-of-view with a small central obscuration. The imager has a dedicated channel with an 18 x 18 arc-minute field of view. The instrument performance in each channel does not degrade the 10th percentile seeing-limited point spread function by more than 10%. We address this stringent requirement by using a novel, wide-angle camera design that is inspired by an Erfle eyepiece. We present the lens design, optical performance, and a tolerance analysis of FALCON.
13096-346
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Mirror-slicer Array for Astronomical Transients (MAAT) is an Advanced Image Slicer (AIS, as the JWST NIRSpec IFU) now being manufactured for the OSIRIS spectrograph on GRANTECAN. Very significant design changes were made due to cost and weight limitations. We present the final design, its expected performances, and the process to get there, in particular the difficulties encountered to avoid variable vignetting in the spectrograph due to the telescope derotator. This includes a new method of AIS extreme optimization and pupil shape modifications. The field is 10" x 7" with 23 slices 0.305" wide; the wavelength range is 360-1000 nm. R will be 1.6 times larger (R=600-4100) than with a 0.6" slit. To maximize the resolution, we measured the spectrograph wavefront by using 2 out-of-focus masks with pinholes along the slit. This showed a residual wavefront, after as-designed wavefront subtraction, variable over the detector due to tolerance aberrations as astigmatism.
Session PS7:
Posters - Instruments Designed with Adaptive Optics Incorporated in the Overall System
20 June 2024 • 17:30 - 19:00 Japan Standard Time
13096-347
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Gran Telescopio de Canarias Adaptive Optics System (GTCAO) is in the commissioning phase at the Roque de Los Muchachos Observatory, boasting a remarkable Strehl Ratio of 65% in the K-band. The system's development culminated in early 2023 following an extensive testing at the Instituto de Astrofísica de Canarias. It was then transported and integrated onto the telescope with meticulous care to prevent deformations and misalignments. This process involved specialized transportation tools and rigorous integration procedures, ensuring that telescope observing hours were not compromised. The paper provides a comprehensive account of this integration, emphasizing mechanical aspects, static and dynamic analyses, and high-precision assembly of opto-mechanical components.
13096-348
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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FRIDA is an infrared (0.9-2.5 μm) imager and integral-field spectrograph that will work in concert with the Gran Telescopio Canarias Adaptive Optics system (GTCAO). It is a diffraction-limited and cryogenic instrument. The image-quality requirements for the complete system (SR>0.9 for K band) necessitate high precision manufacturing and quality control for all the optical components and subsystems.
The glass optics components were manufactured and tested at the UNAM workshops.
The Integral Field Unit is a joint development of the University of Florida and UNAM.
The Integral Field Unit is a slicer type based on University of Florida FISICA. The components were made by diamond turning on a special alloy. Parts of the slicer were manufactured by Corning Specialty materials and by Durham Precision Optics. The integration of those parts was carried out at the University of Florida.
In this presentation we describe the acceptance tests of the IFU as a system by double path interferometry on a ZYGO instrument and by direct estimation of the Strehl Ratio using a confocal microscope at 1.064 microns. The results show an excellent image quality with SR>0.9 for 1.064μm.
13096-349
Overview of the final design of the imaging system for the Gemini Infrared Multi-Object Spectrograph
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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GIRMOS is an infrared multi-object adaptive object spectrograph with four channels and a simultaneous imaging system. The spectrographs and imager are housed within a common cryostat and the adaptive optics and object selection system operates at ambient temperature in front of the cryostat. GIRMOS receives adaptive optics corrected light from the Gemini North Adaptive Optics (GNAO) System in either GLAO or LTAO mode. This paper provides an overview of the requirements and design of the imaging system including prototyping efforts undertaken to de-risk the design. The plan for the fabrication phase of the GIRMOS project, including the assembly, integration and verification for the GIRMOS imaging system will also be described.
13096-350
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Gemini Planet Imager (GPI) is a facility-class instrument designed for directly imaging young Jovian planets. It conducted the GPI Exoplanet Survey (GPIES) at Gemini South from 2014 - 2019, observing exoplanets, brown dwarfs, and protoplanetary disks around young nearby stars. After being taken off the telescope in 2020, GPI has been undergoing a series of changes and upgrades at the University of Notre Dame as part of its transition to Gemini North as GPI 2.0. Major changes have been made to several subsystems of GPI, including upgrades to components of the adaptive optics (AO) system, the integral field spectrograph (IFS), and the calibration subsystem (CAL). We present the procedures taken to install these upgrades, along with their testing and performance when integrated into the overall system in the lab.
13096-351
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Gemini Planet Imager (GPI) is a dedicated high-contrast imaging facility instrument. After six years, GPI has helped establish that the occurrence rate of Jovian planets peaks near the snow. GPI 2.0 is expected to achieve deeper contrasts, especially at small inner working angles, to extend GPI’s operating range to fainter stars, and to broaden its scientific capabilities. GPI shipped from Gemini South in 2022 and is undergoing an upgrade as part of a relocation to Gemini North. We present the status of the upgrades including replacing the current wavefront sensor with an EMCCD-based pyramid wavefront sensor, adding a broadband low spectral resolution prism, new apodized-pupil Lyot coronagraph designs, upgrades of the calibration wavefront sensor and increased queue operability. Further we discuss the progress of reintegrating these components into the new system and the expected performance improvements in the context of GPI 2.0's enhanced science capabilities.
13096-352
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The GRAVITY+ project includes the upgrade of the Very Large Telescope Interferometer infrastructure and of the instrument GRAVITY to improve sky coverage, high contrast capabilities, and faint science. The improved sky coverage is obtained via the implementation of one Laser Guide Star on each Unit Telescope. This first requires an upgrade of the infrastructure of each of the UTs, which was made over 18 months in 2022 and 2023.
13096-353
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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HARMONI is the first light visible and near-IR integral field spectrograph for the ESO-ELT. It covers a large spectral range from 470 nm to 2450 nm with resolving powers from 3300 to 18000 and spatial sampling from 60mas to 4mas. It can operate in four Adaptive Optics modes – SCAO, HCAO, LTAO – or with NOAO. The project is preparing for Final Design Reviews (FDR). The high-contrast module is a dedicated subsystem that will enable the characterization of exoplanets thanks to a second stage ZELDA wavefront sensor, and to shaped pupils to create either a moderate 1e-5 contrast dark hole at a few L/D from the star, or a deeper dark hole with a 1e-6 contrast further away. We provide detection limits derived from the application of ADI and molecular mapping post-processing techniques on both numerical and experimental data for a variety of planets and observing conditions.
13096-354
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The High-Resolution Infrared Spectrograph for Exoplanet Characterization (HISPEC) is a new instrument for the W. M. Keck Observatory that enables R~100,000 spectroscopy simultaneously across the y, J, H, and K astronomical bands (0.98-2.5μm). HISPEC is a fiber-fed echelle spectrograph that leverages the diffraction-limited performance of the Keck II adaptive optics system. In this proceeding, we present the end-to-end throughput budget for Keck/HISPEC including the reflectance and transmittance of the system's mirrors, dichroics, lenses, gratings, etc. as well as supporting numerical simulations of fiber coupling efficiencies considering diffraction, static and dynamic wavefront error residuals, atmospheric dispersion residuals, beam shaping, and realistic fiber modes for both single-mode and few-mode fiber options. We also discuss the sensitivity of the throughput on several key performance parameters, which are essential for determining potential risks to the scientific potential of the instrument.
13096-355
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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SCALES (Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy) is a 2 - 5 micron high-contrast lenslet-based integral field spectrograph (IFS) designed to characterize exoplanets and their atmospheres. The SCALES medium-resolution mode uses a lenslet subarray with a 0.34 x 0.36 arcsecond field of view which allows for exoplanet characterization at increased spectral resolution. We explore the sensitivity limitations of this mode by simulating planet detections in the presence of realistic noise sources. We use the SCALES simulator scalessim to generate high-fidelity mock observations of planets that include realistic Keck adaptive optics performance, as well as other atmospheric and instrumental noise effects. We employ a combination of spectral and angular differential imaging to extract the planet. These simulations allow us to assess the feasibility of planet characterization using the SCALES medium-resolution mode, and to quantify the effects of various systematic noise sources. We also use these simulations to explore SCALES' ability to constrain molecular abundances and disequilibrium chemistry in giant exoplanet atmospheres.
13096-356
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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SPHERE+ is a proposal to upgrade the SPHERE extreme Adaptive Optics instrument at the VLT to boost the current performances of detection and characterization of exoplanets and disks.
The main science drivers for SPHERE+ are 1/ to access the bulk of the young giant planet population down to the snow line; 2/ to observe fainter and redder targets in the youngest associations to directly study the formation of giant planets in their birth environment; 3/ to improve the level of characterization of exoplanetary atmospheres by increasing the spectral resolution.
These objectives can be realized with two new subsystems, SAXO+ and MEDRES. We focus on the former which is a second stage AO system equipped with an IR pyramid wavefront sensor for increasing the sampling frequency (from ~1 to 3 kHz) as well as the sensitivity in the infrared (+2-3 mag). SAXO+ is developed in coordination with the ESO technology development group and will serve as a demonstrator for the future planet finder (PCS) of the ELT. SAXO+ is in a consolidation phase since Oct 2022 to last ~18 months.
We will provide an overview of the project with science cases, system choices and performance estimations
13096-357
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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SAXO+ is a planned enhancement of the existing SAXO, the VLT/ SPHERE adaptive optics system, deployed on the ESO’s Very Large Telescope. The pivotal addition in SAXO+ is a second-stage adaptive optics system featuring a dedicated near-infrared pyramid wavefront sensor and a second deformable mirror.
Several recent studies using focal plane sensors (a Zernike wavefront sensor and the pair-wise probing technique), clearly showed that in good conditions, even in the current system SAXO, non-common path aberrations (NCPA) are the limiting factor of the final normalised intensity in focal plane. This is likely to be even more the case with the new AO system, which will minimized the AO residuals aberrations. However, the use of a new type of detector, a pyramid wavefront sensor, will likely complicate the correction of these aberrations.
Employing COMPASS, an end-to-end AO simulation tool, we conducted simulations to gauge the effect of measured SPHERE NCPA in the coronagraphic image on the second loop system. In a second part, we show that we can correct some of these aberrations using focal plane wavefront sensing systems.
13096-358
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The upcoming Ristretto spectrograph is dedicated to the detection and analysis of exoplanetary atmospheres, with a primary focus on the temperate rocky world Proxima b. This scientific endeavor relies on the interplay of a high-contrast adaptive optics (AO) system and a high-resolution echelle spectrograph. In this work, I present a comprehensive simulation of Ristretto's output spectra, employing the Python package Pyechelle. Starting from realistic spectra of both exoplanets and their host stars, I generate synthetic 2D spectra to closely resemble those that will be produced by Ristretto itself. These synthetic spectra are subsequently treated as authentic data and therefore analyzed. These simulations facilitate not only the investigation of potential exoplanetary atmospheres but also an in-depth assessment of the inherent capabilities and limitations of the Ristretto spectrograph.
13096-359
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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NirvanaVIS is a proposed upgrade in the visible wavelength for LINC-NIRVANA, the Italian-German high angular resolution near-infrared imager installed on the Large Binocular Telescope. LINC-NIRVANA has demonstrated on-sky, a Ground Layer Adaptive Optics correction improving the FWHM of the PSF up to a factor three within a 2 arcmin diameter field of view.. We aim to exploit the AO correction in the visible wavebands (600 to 1000 nm) to achieve AO-assisted speckle holography, in which images are reconstructed from several short exposure frames. We will present the consolidated opto-mechanical design, featuring an 8K fast-frame CMOS, identified to allow this additional mode. We will focus on analysis, trade-offs, simulations, and compromises taken to reach our science objectives, including ways to solve the extra challenge given by a huge amount of data to be acquired and stored while keeping all functionalities of the NIRVANA instrument.
13096-360
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The 4 K two-stage pulse tube cryocoolers have been used in Cosmic Microwave Background (CMB) Telescopes to increase the sensitivity of instruments and enable low temperature detector technologies.
Bluefors Cryocooler Technologies has been continuously improving cooling capacity and energy efficiency of its 4.2 K two-stage pulse tube cryocoolers. The two newest models, the PT425 (2.7 W at 4.2 K) and PT450 (5.0 W at 4.2 K), have been successfully developed and launched in 2021 and 2023, respectively. The PT450 is the world’s largest, commercially available, 4 K pulse tube cryocooler, which provides a minimum of 5.0 W at 4.2 K on the 2nd stage with 65 W at 45 K on the 1st stage simultaneously.
The cooling performance of a pulse tube cryocooler is tied to the tilt angle of the system relative to the gravity vector, such that the cooling capacity decreases as a function of the tilt angle. The gas gravitational effect on the cooling performance of the PT425 and PT450 has been experimentally investigated. Test results of the tilt angles ranging from 0° (vertical) to 60° are presented in this paper, providing an accurate reference for the tilted cryogenic system design in CMB telescopes.
13096-361
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The NASA-funded Exoplanet Climate Infrared Telescope (EXCITE), a high-altitude balloon-based near-infrared spectrograph with a 0.5-meter mirror, operates in two channels (0.8 - 2.5μm and 2.5 – 4μm) to measure spectroscopic phase curves of transitioning hot Jupiter-type exoplanets. Housed in a Dewar at a temperature of 120K, the sub-zero environment induces thermal contraction, posing risks of mechanical failures and misalignment within the optical assembly. The opto-mechanical system is intricately designed to minimize optics displacement and prevent substantial stresses, mitigating potential misalignments and distortions. Leveraging Finite Element Analysis (FEM), the study predicts and refines optics displacement and stress, ensuring compliance with requirements and incorporating safety margins. This paper provides in-depth insights into the opto-mechanical design of the optics mounts in the spectrograph.
13096-362
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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ALTAIR, the Gemini North single conjugated Adaptive Optics system has been Gemini AO facility instrument since 2003. Used every single night for the Gemini primary mirror tunning, ALTAIR has been allocated for GEMini NIR instruments science programs including the Near Infrared Integral-field Spectrograph (NIFS), the Near Infrared Imager (NIRI) and the Gemini multi-function spectrograph (GNIRS).
In this proceeding, we propose to review the actual performances of our 20 years old AO system. We will also describe the main instrument failure (Slow focus camera, Deformable mirror) that we had to fix to keep ALTAIR alive until the GNAO instrument venue (5 years from now).
13096-363
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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One method used for high-contrast coronagraphs is the vector vortex phase mask, and a 6th-order one is required to sufficiently suppress the light from stars using future large telescopes at the ground and in space. We fabricated 12- and 24-segmented sixth-order vector vortex phase masks with photonic crystal waveplates. A three-layer structure was designed to cover a broad band. The retardation of the phase mask was almost coincident to the design curve, but the measured contrast was not sufficient. As for the 24-segment phase mask, a shaped pupil was designed as a combined element to exhibit the performance of the phase mask in the pupil shape of the TMT. The shaped pupil design has a transmittance of about 70% and a contrast of 1E-7 within the outer working angle of 10 lambda/D. The shaped pupil was fabricated and got the reduction of the diffracted light within 8 lambda/D.
13096-364
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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ULTIMATE-Subaru is a next generation wide field NIR imaging camera with ground layer adaptive optics being developed for the Subaru telescope. Here we present the current sensitivity performance estimates for the instrument. In the ideal conditions of good (25%) seeing, airmass of 1, water vapor of 1.6 mm and 1 hour exposure time, we reach 5 sigma point source depths of 25.6, 25.5, 25.2 and 25.4 mags in YJHKs respectively. With GLAO there is a general improvement of 0.3~0.4 mags in depth across all bands compared to natural seeing. We have also modeled the fractional noise contribution in the NIR from sky background, telescope thermal background, moon background and read noise. We find that sky background is the dominant source of noise across most NIR bands, apart from the K-band, where the thermal emission from the telescope becomes a significant source of noise. Our results indicate that K-band observations using ULTIMATE-Subaru with GLAO under ideal observing conditions could potentially reach comparable sensitivities to that of Roman telescope, given that instrument thermal emission remains an important noise component in both ground and space telescopes at this wavelength.
13096-365
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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SHARK-VIS the new, AO assisted, high contrast imager at the LBT operating at visible wavelenghts (400-950 nm) because of its high angular resolution of 15-20 mas it is well suited for the search of young forming Exoplanets. Its search cababilities may be further extended to the inner region of a star forming disk, in the range of 15-100 mas where also coronagraph are not efficient, boosting its sensistivity to the H-alpha line emission with the addition of some spectroscopic capabilities by means of custom optical devices (GADGETS) or add-on spectroscopes. This work describes the most relevant tools we are developing for SDI imaging and some novel designs for very compact and minimal spectroscopes to be integrated within the SHARK-VIS imager in the next future for the ELVIS and ROSES projects both based on the detection of the H-alpha emission line generated from the Hydrogen infall on the forming planet.
13096-366
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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We propose a wavefront error compensation system based on phase diversity and a spatial light modulator (SLM) for a solar spectropolarimeter space instrument. The phase diversity technique has been successfully used in balloon borne instruments (IMaX and TuMag) and in space-borne instruments (SO/PHI). The method requires either two cameras observing the same scene with a known phase difference (usually a defocus), or a mechanism that induces the optical path difference on the same sensor sequentially. We demonstrate this functionality using a SLM instead of a physical mechanism. A liquid crystal-based SLM can provide different levels of defocusing as well as other wavefront aberrations. This flexibility enables different procedures for a dynamic wavefront retrieval system. The approach allows direct acquisition of corrected images. Moreover, the compactness and low power requirements of SLMs can be of great advantage. We show preliminary results using the IMaX optical layout as the baseline for our demonstrator.
13096-367
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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We describe the coronagraphic upgrade underway for the Mid-Infrared Array Camera-5 (MIRAC-5) to be used with the 6.5-m MMT telescope utilizing the new MMT Adaptive optics exoPlanet characterization System (MAPS). Mid-IR ground-based coronagraphic adaptive-optics-assisted-imaging can be a powerful tool in characterizing exoplanet atmospheres and studying protoplanets in formation within circumstellar disks around young stars. In addition to enabling ground-based observations of bright targets in the background limit, new adaptive optics capabilities of such systems can outperform JWST in the contrast limit. We are in the process of: a) procuring an annular groove phase mask (AGPM) coronagraph; b)interfacing the Quadrant Analysis of Coronagraphic Images for Tip-tilt Sensing (QACITS) control loop algorithm with MAPS on the MMT; c) designing and procuring an optimized Lyot stop for use with the AGPM. We will give an overview of the system, describe the pupil mask design and fabrication including thermal infrared testing, and compare expected performance to requirements driven by our scientific goals.
13096-368
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Flamingos-2 (F2), mounted on the Gemini South telescope, offers imaging, long-slit and multi-object spectroscopy across various near-infrared bands. When paired with GeMS, a Multi-Conjugate Adaptive Optics System (MCAO), it creates a remarkable astronomical tool in the Southern hemisphere. The feasibility study indicates that the on-sky field of view encompasses a 2.37 arcmin diameter. GeMS LGS+F2 long-slit tests achieved a spatial profile FWHM of around 0.17 arcsec (1.9 pixels). The instrument's long-slit covers 1.6 arcmin in the sky. MOS masks are capable of accommodating up to 48 slits in sparse fields and around 80 targets in crowded or extended fields. Anticipated background issues are minimal in the J and H bands, while comprehensive testing is essential to evaluate thermal background in the K band. Incorporating GeMS alongside F2 significantly improves spectral resolution, particularly at spectral range edges. Finally, a noteworthy outcome of the study reveals that F2 with GeMS in non-LGS mode produces a “super-seeing” mode with enhanced image quality by a factor of 2 or more.
Session PS8:
Posters - Multi-messenger Astronomical Instruments
20 June 2024 • 17:30 - 19:00 Japan Standard Time
13096-369
20 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We present the status of an upgrade to the Robert-Stobie Spectrograph (RSS) on the Southern African Large Telescope (SALT). The instrument upgrade is primarily aimed at efficient identification spectroscopy of transients. The updated design extends the existing RSS by adding a new simultaneous red channel for wide visible wavelength coverage (360 nm to 900 nm). The design delivers R ~600 in the blue channel using the existing RSS optics and R ~2000 via the new red channel. We present the current status of the project, the instrument design and expected performance.
13096-370
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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SuperSMART is a novel concept to enable medium resolution optical and near-IR spectrophotmetry for a wide range of science cases, with a specific focus on the field of Time Domain Astronomy. It is based around an array of 'small' (0.6-1.0m) commercial telescopes which each feed light independently via one or more fibers to a cryostat containing an array of Microwave Kinetic Inductance Detectors (MKIDs). This array forms a number of channels of a medium spectral resolution (R=5-10,000) wide passband (350-1800nm) spectrograph, using the KIDSpec concept (O'Brien, JLTP, 2020). Each telescope in the array would feed three fibers; one each for the target, a comparison target and a simultaneous sky measurement. By combining the spectra from multiple telescopes incoherently, SuperSMART leverages the much improved cost/aperture of prosumer robotic telescopes, compared to standard 4-8m monolithic telescopes. In this presentation, we will present the concept, some potential configurations and simulations of science cases that highlight the unique science that could be obtained.
13096-371
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Pathfinder IFU is a project to augment Canada-France-Hawai‘i Telescope’s (CFHT) suite of spectrographic instruments with integral field unit capability in the visible band (360 to 1000 nm). Pathfinder will work alongside VISION, a combination of the ESPaDOnS and SPIROU visible and infrared spectropolarimeters, to provide unique rapid follow-up coverage of targets discovered by multi-messengers and external surveys. Pathfinder will leverage off the DESI spectrograph design, baselining a single ~500 fiber IFU feeding one DESI spectrograph, with the possibility of future upgrade to a second identical IFU and spectrograph. The IFU will have a 3' patrol field allowing it to be used simultaneously with VISION on deep objects requiring long integration times, possibly over repeated visits, and over a field that is subordinate to the primary target defined by the VISION observation. This paper describes the preliminary concept for the IFU configuration and the optical design of the off-axis corrector, ADC, and transfer optics needed to efficiently couple light into the DESI spectrograph.
Session PS9:
Posters - New Technologies which May be Transformative in Future Instrument Design
20 June 2024 • 17:30 - 19:00 Japan Standard Time
13096-372
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The CTA+ project foresees the enhancement of the Cherenkov Telescope Array Observatory (CTAO) Southern Site in Paranal, Chile. The project aims at increasing the number of telescopes included in the baseline CTA configuration, called the “alpha” configuration. A R&D program is foreseen to improve the technology for a future upgrade of the CTAO southern site. CTA+ aims at developing sensors for a high-resolution Cherenkov camera to upgrade the current camera designs. Silicon Photomultipliers (SiPMs) with a very high sensitivity in the Near Ultraviolet (NUV) wavelength range and low correlated noise are under consideration. The R&D program will include specific developments of the Through-Silicon-Via technology, for a compact packaging with minimization of dead spaces among pixels.
13096-373
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Prime Focus Spectrograph (PFS), a next-generation instrument being installed on the 8.2m Subaru Telescope, is a very wide-field, massively multiplexed, optical and near-infrared spectrograph. For its successful science operation, high-quality sky subtraction is of crucial importance to accurately extract weak galaxy signals. To achieve that, we are now developing modeling algorithms to determine the 2D point spread function (PSF) at arbitrary positions on the spectrograph detectors. The light coming into the detectors is affected by various components of the instrument before being observed as the final PSF, such as the telescope pupil illumination, focal ratio degradation in the fibers, and various aberrations of the spectrograph optics. We model the PSF by combining optical models of all these effects. Comparing the model with the data taken in commissioning observations, we determine over a hundred parameters. We present the current status of this PSF modeling.
13096-374
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Canada-France-Hawaii telescope (CFHT), as a precursor to the Maunakea Spectroscopic Explorer (MSE) project, plans to develop an end-to-end Pathfinder instrument for use on CFHT. The MSE-Pathfinder will have both an Integral Field Unit (IFU) and Multi-Object Spectrograph (MOS) capabilities and will be developed on an accelerated timescale at CFHT in tandem with collaborators. Among the primary science goals of the Pathfinder are time-domain astrophysics, specifically spectroscopic follow-up of transients identified by facilities such as Rubin Observatory and Zwicky Transient Factory to optimize their identification and classification; Galactic archeology; and the resolved spectroscopy of galaxies, which drive the science requirements. The Pathfinder will prototype the software architecture for MSE including, scheduling; targeting; data reduction and analysis; and data management, archiving and database manipulation.
13096-375
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The completely open dome provides excellent dome Seeing, but at the same time wind loads are applied directly to the telescope, and the wind screen structure can be a good solution to this contradiction. The effects of the wind screen structure on the wind speed around the telescope, dome Seeing, mirror wind pressure, etc. are investigated by simulation and wind tunnel tests, and the optimal wind screen transmittance, structural rod size, and the distance between the wind screen and the telescope are finally obtained.
13096-376
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Most optical spectropolarimeters built to date operate as long-slit or point-source instruments; they are inefficient for observations of extended objects such as galaxies and nebulas. 2D spectropolarimetry is a major challenge in astronomical polarimetry, with the promise of rich scientific dividends.
At South African Astronomical Observatory’s (SAAO) FiberLab, we are developing a spectropolarimetry capable Integral Field front end called FiberPol(-6D) for the existing SpUpNIC spectrograph on the SAAO’s 1.9 m telescope. FiberPol is a low-cost technology demonstrator (< 10,000 USD), and the entire system predominantly employs small size (1 inch or less), commercial off-the-shelve optics and optomechanical components. FiberPol can be modified for use on any existing spectrograph, especially on bigger telescopes like the 10 m South African Large Telescope (SALT) and the upcoming 30 m class telescopes.
The instrument design has been completed. It is scheduled for lab assembly, characterization in early 2024 and subsequent on-sky commissioning in second half of 2024.
13096-377
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Multiplexed surveys have the ambition to grow larger for the next generation of focal plane instruments. Future projects such as Spec-S5, MUST, and WST have an ever-growing need for multi-object spectroscopy (>20 000 simultaneous objects) which demands further investigations of novel focal plane instrumentation. In this paper, we present a rigorous study of focal plane coverage optimization and assembly of triangular modules of theta-phi fibre positioners with a 6.2 mm pitch.
The main focus here is to examine different module arrangements in the focal plane, namely, framed, semi-frameless, and fully-frameless assemblies. The following paper will also present their capabilities to meet the requirements for focal plane assembly such as focus, tilt, coverage, etc.
13096-378
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Multiplexed surveys have the ambition to grow larger for the next generation of focal plane instruments. Future projects such as Spec-S5, MUST, and WST have an ever-growing need for multi-object spectroscopy (>20 000 simultaneous objects) which demands further investigations for novel fiber positioning systems for such high density needs.
This paper introduces the testing and characterization of an innovative next-generation fiber positioner featuring an ultra-fine 6.2 mm pitch. The evaluation criteria encompass positional accuracy, repeatability, fiber alignment, and thermal stability. The findings offer valuable insights into the performance and suitability of this advanced positioning technology, emphasizing its potential to enhance the success of the future projects and similar endeavors in the field of precision optical instrumentation.
13096-380
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Optical fibers, with their immunity to electromagnetic interference, can offer long-range signal transmission for radio telescopes, substituting coaxial cables. We propose a novel, economical approach by adapting commercial digital Small Form-factor Pluggable (SFP) modules for analog Radio-over-Fiber (RFoF) usage. By repurposing these modules with tailored analog circuits, we can transmit RF signals up to several gigahertz. Initial tests with a 3m LC fiber achieved flat, low-loss transmission for bands greater than 2 GHz. This presentation will detail our design and testing for such modified SFP modules, promising significant benefits for radio astronomy.
13096-381
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The detection of celestial Positronium (Ps) is crucial for understanding positron origins. Traditional gamma-ray detection is inherently limited to a 2.7-degree angular resolution, while detection through the Ortho-Ps recombination lines in the near-infrared can enhance the angular resolution by approximately 1000 times, thereby offering the potential to resolve point sources. We already proposed a design of the first OH-suppressed multimode diffraction-limited spectrograph for celestial Ps detection at NIR wavelengths, using novel astrophotonic techniques such as photonic lanterns and aperiodic multi-notch fiber Bragg gratings. In this proceeding, we will show the construction details and preliminary in-lab test results for this spectrograph.
13096-382
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The AMASE-P project presents a bold exploration into the potential utilization of state-of-the-art commercial photographic lenses and CMOS detectors as integral components in spectrograph designs, thereby offering a cost-effective solution for astronomy instrumentation. In this contribution, we present the current optical design of the telescope and spectrograph system, and present the expected performance of the design, including the point spread function, spectral resolution, throughput, and signal-to-noise ratios. We also present the design of a telecentric corrector for the Canon 400mm f/2.8 III telephoto lens, which is necessary for coupling it to optical fibers.
13096-383
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Fiber based Fabry-Perot interferometers offer high precision calibration lines for astronomical spectrographs such as ELT-MICADO in a compact form factor with remote access. Since the calibration lines are carried in optical fibers, a distribution model is possible at very low costs. The fabrication methods described in this paper can achieve different FSRs and finesse over the astronomical J-, H-, and K-band.
13096-384
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Photonic lanterns predictably decompose the inherently multimode light from a ground-based telescope
into a series of single-mode outputs, thus eliminating the need for exotic optical elements or extreme AO to
achieve high efficiency (Jovanovic et al., 2017). We have built a custom assembly for the AO system at Lick
Observatory’s 3m Shane Telescope to test photonic lantern behavior on-sky. Here we report on multiple nights
of observations over the past year using a lantern with a design wavelength of 1550 nm. Our data reveals
the lantern’s basic performance over 630–1000 nm, its wavelength dependent throughput, and its time domain
response to turbulent PSFs as well as AO correction residuals. By inserting a grating, we also measure the
time-varying wavelength dependence of the lantern’s modal decomposition.
13096-385
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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In our previous reports, we detailed the development of the Beam Switch Module (BSM) for the VIRUS2 instrument and its integration/test result to demonstrate its potential for such capability. Fundamentally, the BSM distills the beam switching functions that many traditional spectrographs accomplished inside the spectrograph themselves into an independent module outside the spectrographs, but at the same time adding a double beam scrambling and fiber switching functions, thereby making the instrument compact, modular, stable, and scalable. Inevitably, having a separate BSM means extra throughput loss due to additional components involved. Our BSM prototype effort and previously presented the first production BSM (BSM1) has shown this “perceived” throughput loss can in fact be minimal when compared to a hypothetical instrument that functions equivalently to the VIRUS2, and, in return, the instrument can be much more adaptable to potential missions that would otherwise have to be done by building a completely new instrument. We subsequently constructed BSM2 and integrated/tested a fully assembled VIRUS2 IFU connected to the BSM. We detail the results of this effort.
13096-386
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Current Skipper CCD technology has been in use in particle physics experiments since its successful testing in 2017 at Fermilab and LBNL[3] while achieving readout noise values as low as 0.039 e-[4]. This extremely low noise presents a very interesting potential for certain astronomical applications where the background photon noise does not dominate, and the ability of Skipper CCDs to be tuned for a desired readout noise allows for a wide range of applications.
In this current paper we present the engineering work performed in cryo-mechanics and electronics (Dewar, detector mount, preamplifier, etc.) at NOIRLab-CTIO to test a 4-Skipper CCD mosaic on sky with the SOAR Integral Field Spectrograph (SIFS). This work was performed in the context of a NOIRLab/FermiLab/U.Chicago/LBNL collaboration for testing of the Skipper devices on the sky.
We also present the mosaic characterization results of the detectors from the laboratory, as well as the final engineering performance results from on sky observations.
13096-387
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Multi-fiber spectroscopy plays an important role in shaping our understanding of structure formation. Enabled by this technology, the first comprehensive maps of the universe, for instance, allowed for the measurement of the universe’s expansion rate through the Baryon Acoustic Oscillation method. Concept studies for a next-generation large spectroscopic survey facility expect a tenfold increase in the number of galaxy and quasar redshifts. This will enable the measurement of over a hundred million spectra, predominantly at z > 2.
An increase by almost a factor of 5 in the number of multiplexed fibers, compared to current-generation instruments such as DESI, necessitates the development of smaller pitch fiber positioners. Efforts are currently underway to scale up mature technology based on the DESI theta-phi actuator design and to develop small-pitch robot prototypes.
However, the theta-phi architecture presents limitations in the achievable target density. While tilting spines can overcome this limitation, they result in an undesirable loss of throughput. Our discussion will focus on positioning technologies and R&D efforts to develop next-generation positioners.
13096-388
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Integrated photonics can be used for stable, cost-effective and precision instruments in astronomy. We present our development and testing of a silicon ring resonator as a tunable correlation filter, facilitating real-time gas contrast for specific molecules with low cross-sensitivity. Ring resonators for various gases in H-band, polarization-selective filters, and fiber-coupled prototypes are described. We present the first on-sky demonstration of silicon-on-insulator astrophotonics, and telluric CO2 absorption feature detection as a proof-of-concept using the 1.2m DAO telescope and REVOLT adaptive optics instrument. Comparisons with traditional spectrographs inform discussions on improving performance and extensions towards an observatory-class instrument for exoplanet biosignature detection.
13096-389
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The Cryoscope Telescope will be deployed during Summer 2024 at Dome C in Antarctica. Local temperature ranges from -80° C to -30° C, far lower than the typical Commercial or Industrial range of most electronics that is usually rated down to -40C. We describe the thermal model for the interior of the cryostat, as well as the choices made to ensure that external electronics will continuously operate in such environment after a cold start at -80° C.
13096-390
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The EXoplanet Climate Infrared TElescope (EXCITE) is a near-infrared spectrograph (0.8-4μm, R~50) designed for measuring spectroscopic phase curves of transiting hot Jupiter-type exoplanets that operates off a high-altitude balloon platform. Phase curves produce a combination of phase curve and transit/eclipse spectroscopy, providing a wealth of information for characterizing exoplanet atmospheres. EXCITE will be a first-of-kind dedicated telescope uniquely able to observe a target nearly uninterrupted for tens of hours, enabling phase curve measurements, and complementing JWST.
The spectrometer has two channels, a 0.8-2.5 μm band and a 2.5-4.0 μm band, providing a spectrum with an average spectral resolution of R~50. Two Off-Axis Parabolic (OAP) mirrors, with a CaF2 prism providing dispersion, reimage the telescope focal plane to provide on-axis, diffraction-limited performance. The spectrum is imaged with a single JWST flight spare Teledyne H2RG detector, providing Nyquist sampling of each channel. Here, we discuss the spectrograph assembly and integration as well as laboratory characterization and acceptance testing.
13096-391
20 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
A multiple fiber fed spectrograph comprised of a stack of photonic echelle spectrographs was first proposed by Watson in 1995 (Proc. SPIE 2476). A single photonic arrayed waveguide grating (AWG) spectrograph fed by 12 single mode fibers was demonstrated in 2012 (A&A 544, L1). CAWSMOS is the next evolution of the photonic spectrograph PAWS (Astron.Nachr., e20230089) with an integral field unit (IFU), capable of analyzing the full field-of-view of the telescope using multiple fibers, photonic lanterns (PLs) and stacked AWGs.
13096-392
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The FlyEye design makes its debut in the NEOSTEL by OHB-Italia. This pioneering FlyEye telescope integrates a monolithic 1-meter class primary mirror feeding 16 CCD cameras for discovering Near-Earth Object (NEO) and any class of transient phenomena. OHB-Italia is the prime contractor, receiving crucial support from the Italian National Institute for Astrophysics (INAF) in the NEOSTED program's integration and testing.
The FlyEye distinctive design splits the Field of View into 16 channels, creating a unique multi-telescope system with a panoramic 44 square degree Field of View and a seeing-size pixel-scale, enabling NEOs detection down to apparent magnitudes 21.5.
The FlyEye astronomical science complements facilities like LSST and ZTF. Placed atop Mount Mufara in Sicily and robotized, FlyEye ability to survey two-thirds of the visible sky about three times per night can revolutionize time-domain astronomy, enabling comprehensive studies of transient phenomena, placing FlyEye in a new era of exploration of the dynamic universe. Efforts to develop automated calibration and testing procedures are keys to realizing this transformative potential.
13096-393
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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In the framework of STILES PNRR Project and as a natural evolution of the INAF Minigrant project on the Integrated approach to the mechanical design for Astronomical Instrumentation, was funded an advanced mechanical engineering laboratory inside the INAF - Observatory of Naples. This facility represents a leap forward in technological research applied to design and development of Ground-based Telescope Instrumentation for the INAF researchers. The role of the new laboratory for mechanical engineering is essentially to support the advanced design, prototype with different Additive Manufacturing 3D printers, maintain state-of-the-art for astronomical instruments and equipment and revamp/retrofit the existent facilities utilizing also the Reverse Engineering approach. The real innovation of this laboratory is represented by the technologies and techniques that will be implemented inside it. Another focus is on Metrology applied to characterize, control and accept the mechanical items designed validated by FEA approach. The synergy between these disciplines promises to improve the scientific collaboration and the technological expertise for INAF researchers of Naples.
13096-394
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Modern fiber-fed astronomical instruments are no longer bound by static, single-field observations; advances in focal plane fiber positioning systems have revolutionized the field. Whilst fiber positioning is now performed by expensive and sensitive robotic systems that are typically fixed in place on a densely-packed focal plane, the next generation of instruments will strive to regain the advantages of a flexible focal plane whilst retaining short reconfiguration times and a highly efficient fiber system. In this paper we present a solution in the form of high-throughput 1-to-many fiber switches . An array of such switches, a ``fiber switchboard,'' could be incorporated into any fiber instrument and would offer a multitude of powerful enhancements. Our scheme is applicable to both new instrument concepts and upgrades of existing instruments.
13096-395
20 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
We measure the contrast ratio and efficiency of a DLP7000 digital micromirror device (DMD) installed in SAMOS: a DMD-based multi-object spectrograph and imager covering a wavelength range of 4000 Å to 9500 Å. In astronomy, DMDs modulate the light intensity of the field and are used as reconfigurable slit masks for multi-object spectrographs. The micromirror array structure induces wavelength-dependent interference that affects the contrast ratio of the device and throughput of the spectrograph. Additionally, the variation in throughput is a function of the micromirror array configuration that composes a pseudo slit. We predict the device performance using a previously developed finite-difference time-domain simulation and compare these results to in-situ measurements using SAMOS. We predict an average contrast of 7990:1 for the DLP7000 while measuring an average contrast of 6370:1 using SAMOS. We further investigate how creating pseudo slits composed of multiple micromirrors can cause up to a 10% sinusoidal variation in efficiency with respect to wavelength. These results inform current and future astronomical instruments incorporating DMDs.
13096-396
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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The use of adaptive optics to realize diffraction-limited telescopes in the infrared enables the use of single-mode photonic devices, which work independent of the telescope diameter. This can dramatically reduce costs, mass, and volume constraints. A possible single-mode counterpart to conventional spectrographs with bulk optics are photonic spectrographs on arrayed waveguide grating (AWG). We developed an AWG for the astronomical J band (center wavelength 1250 nm). The device has been fabricated and was characterized using a test bench built in-house. The AWG was found to display spectral resolutions close to the design resolution R ~12000, over a much larger working range than expected. Our results demonstrate the possibility and potential to use AWG in astronomical spectrographs in future instruments.
13096-397
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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We present flattened supercontinuum generation from micro-resonator-based frequency comb for the calibration of astronomical spectrographs. Micro-resonator-based frequency combs, also known as microcombs, exhibit inherently high mode spacing owing to their compact cavity size. That simplifies an astronomical laser frequency comb system by bypassing the mode filtering process. Applying a tailored photonic crystal fiber (PCF) taper, the spectrum of a 12 GHz microcomb is broadened to more than one octave from 1 µm to 2.2 µm. The resulting supercontinuum is smoothed using a spatial light modulator based spectral flattener, producing a flat-top broadband supercontinuum that serves as a powerful source for precision astronomical spectroscopy.
13096-398
20 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Small and compact optics are a key element for future small missions, in particular cubesat.
We started the miniaturization concept study in order to adapt the idea to the small cubesat envelope; lab tests on representative units are in progress, as part of a INAF Mini Grant awarded in 2022.
In particular, we aimed at simplification of the initial design, in order to cope with costs and available space.
Preliminary results are shown in this paper.
We study standard reflective coatings and propose an innovative approach for future development of the design.
We characterize the telescope and put it into the experimental perspective of a ground based instrument, trying to identify and solve the main issues towards the subsequent spatialization.
13096-399
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Leveraging the observational power of magneto-optical filters (MOFs), we present a new low-cost, robotic network for space weather observations. This network consists of two nodes located in La Palma, Spain and Apple Valley, California, USA. We present preliminary data from this new network and the technical specifications for the future operation of the network.
13096-400
20 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
Fiber mode scrambling remains a key technology for fiber-fed EPRV measurements. Any change in mode excitation within the fiber will result in apparent centroid shifts (and thus artificial RV shifts) in the target spectrum. Technologies such as scramblers and mechanical agitators are currently used to mitigate this effect. Here, we present our experimental results on the modal illumination stability of “flat top” optical fibers. These fibers are fabricated with deliberately-introduced internal mode scrambling features which distribute light evenly among the fiber modes during transmission from input to output. Importantly, this scrambling occurs with minimal (few percent) light losses and without external optical alignment or mechanical motion to achieve excellent mode scrambling if the flat-top fiber is spliced into the existing fiber feed. We will present our measurements of flat-top fiber throughput and scrambling gain, and the expected benefits from incorporating such a fiber into existing EPRV spectrographs.
13096-401
20 June 2024 • 17:30 - 19:00 Japan Standard Time
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Studying binary systems with close, faint companions requires high-resolution, high-contrast imaging. The ‘Alopeke speckle instrument, located at Gemini North, detects such binary systems. We optimize the spatial resolution in our speckle data using the multi-frame blind deconvolution (MFBD) technique. However, as the optical aberrations are static, their contribution to the blurring of the image remains in the digitally restored object estimate, thus limiting the achievable resolution. However, this residual image blur can be removed by an additional single-frame blind deconvolution. The estimated aberrations from this second step show excellent agreement with the expectations for the aberrations of the ‘Alopeke instrument and pave the way for improved optical alignment. This technique can be used for any speckle imaging system.
13096-402
20 June 2024 • 17:30 - 19:00 Japan Standard Time
Show Abstract +
VIPA is a fiber-fed, compact, high-resolution (R~80000), NIR, cross-dispersed spectrometer with a high (~40%) transmission. It is designed to characterize simultaneously two diffraction-limited sources, such as an exoplanet observed in high-contrast imaging, and a calibration source. After a successful operationality demonstration at Palomar Observatory in 2022, we report here our further development strategy towards an optimized, competitive and ready-to-use instrument on large-scale telescopes: upgrades will significantly increase the observing efficiency with a new scientific grade H2RG detector, with a new cross-disperser allowing to enlarge the spectral bandpass from 130nm to 215nm, and with a new bench opening the K band. We also report on the next on-sky observations with VIPA, this time at the Observatoire de Haute Provence, using the PAPYRUS XAO system, and a fiber injection unit inspired by the HiRISE and KPIC projects to feed the spectrometer with the light of stellar-mass companions observed at the T152 telescope.
Program Committee
Carnegie Obervatories (United States), GMTO Corp. (United States)
Program Committee
South African Astronomical Observatory (South Africa)
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