Status of resolve instrument onboard x-ray imaging and spectroscopy mission (XRISM)
Yoshitaka Ishisaki, Richard L. Kelley, Hisamitsu Awaki, Jesus C. Balleza, Kim R. Barnstable, Thomas G. Bialas, Rozenn Boissay-Malaquin, G. V. Brown, Edgar R. Canavan, Renata Cumbee, Timothy M. Carnahan, Meng P. Chiao, Brian J. Comber, Elisa Costantini, Jan-Willem A. den Herder, Johannes Dercksen, C. P. de Vries, Michael DiPirro, Megan E. Eckart, Yuichiro Ezoe, C. Ferrigno, Ryuichi Fujimoto, Nathalie Gorter, Steven M. Graham, Martin Grim, Leslie S. Hartz, R. Hayakawa, Takayuki Hayashi, Natalie Hell, Akio Hoshino, Yuto Ichinohe, M. Ishida, Kumi Ishikawa, Bryan L. James, Steven J. Kenyon, Caroline A. Kilbourne, Mark O. Kimball, Shunji Kitamoto, Maurice A. Leutenegger, Yoshitomo Maeda, D. McCammon, Joseph J. Miko, Misaki Mizumoto, Takashi Okajima, Atsushi Okamoto, S. Paltani, F. S. Porter, Kosuke Sato, Toshiki Sato, Makoto Sawada, Keisuke Shinozaki, R. F. Shipman, Peter Shirron, Gary A. Sneiderman, Yang Soong, Richard Szymkiewicz, Andrew E. Szymkowiak, Yoh Takei, Keisuke Tamura, Masahiro Tsujimoto, Yuusuke Uchida, Stephen Wasserzug, M. C. Witthoeft, Rob Wolfs, Shinya Yamada, Susumu Yasuda
Abstract
The resolve instrument onboard the X-Ray Imaging and Spectroscopy Mission (XRISM) consists of an array of 6 × 6 silicon-thermistor microcalorimeters cooled down to 50 mK and a high-throughput x-ray mirror assembly (XMA) with a focal length of 5.6 m. XRISM is a recovery mission of ASTRO-H/Hitomi, and the Resolve instrument is a rebuild of the ASTRO-H soft x-ray spectrometer (SXS) and the Soft X-ray Telescope (SXT) that achieved energy resolution of ∼5 eV FWHM on orbit, with several important changes based on lessons learned from ASTRO-H. The flight models of the Dewar and the electronics boxes were fabricated and the instrument test and calibration were conducted in 2021. By tuning the cryocooler frequencies, energy resolution better than 4.9 eV FWHM at 6 keV was demonstrated for all 36 pixels and high resolution grade events, as well as energy-scale accuracy better than 2 eV up to 30 keV. The immunity of the detectors to microvibration, electrical conduction, and radiation was evaluated. The instrument was delivered to the spacecraft system in 2022-04 and is under the spacecraft system testing as of writing. The XMA was tested and calibrated separately. Its angular resolution is 1.27′ and the effective area of the mirror itself is 570 cm<sup>2</sup> at 1 keV and 424 cm<sup>2</sup> at 6 keV. We report the design and the major changes from the ASTRO-H SXS, the integration, and the results of the instrument test.