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Proceedings Paper

Sparsity and cosmology: inverse problems in cosmic microwave background experiments
Author(s): F. C. Sureau; J. Bobin; J.-L. Starck
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Paper Abstract

We propose a new method to better estimate and subtract the contribution of detected compact sources to the microwave sky. These bright compact source emissions contaminate the full-sky data over a significant fraction of the sky, and should therefore be accurately removed if a high resolution and full-sky estimate of the components is sought after. However the point source spectral variability hampers accurate blind source separation, even with state-of-the-art localized source separation techniques. In this work, we rather propose to estimate the flux of the brightest compact sources using a morphological separation approach, relying on a more sophisticated model for the background than in standard approaches. Essentially, this amounts to separate point sources with known support and shape from a background assumed sparse in the spherical harmonic domain. This approach is compared to standard local χ2 minimization modeling the background as a low order polynomial on WMAP realistic simulations. If in noisy situations estimating more than a few parameter does not improve flux recovery, in the first WMAP channels the proposed method leads to lower biases (typically by factors of 2) and increased robustness.

Paper Details

Date Published: 26 September 2013
PDF: 11 pages
Proc. SPIE 8858, Wavelets and Sparsity XV, 885811 (26 September 2013); doi: 10.1117/12.2024040
Show Author Affiliations
F. C. Sureau, Lab. AIM, UMR CEA-CNRS (France)
J. Bobin, Lab. AIM, UMR CEA-CNRS (France)
J.-L. Starck, Lab. AIM, UMR CEA-CNRS (France)


Published in SPIE Proceedings Vol. 8858:
Wavelets and Sparsity XV
Dimitri Van De Ville; Vivek K. Goyal; Manos Papadakis, Editor(s)

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