Optimization of X-ray event screening using ground and in-orbit data for the Resolve instrument onboard the XRISM satellite

The Resolve instrument onboard XRISM hosts an X-ray microcalorimeter detector, which is expected to achieve a high-resolution (≤7 eV@6 keV), high throughput, and non-dispersive spectroscopy over a wide energy range (0.3-12 keV). Event screening to discriminate X-ray events from noise is important for the instrument to work in a large dynamic range of energy and flux. We obtained new data sets with an extended ground calibration program and in-orbit data, which we used to verify and optimize the screening criteria. We examined screening based on (1) the good-time-intervals, (2) relative event timing, and (3) pulse shape. The screening results are presented and the optimized parameters are implemented in the calibration data base.