Comparing XRISM cluster velocity dispersions with predictions from cosmological simulations: are feedback models too ejective?
Abstract
The dynamics of the intra-cluster medium (ICM), the hot plasma that fills galaxy clusters, are shaped by gravity-driven cluster mergers and feedback from supermassive black holes (SMBH) in the cluster cores. XRISM measurements of ICM velocities in several clusters offer insights into these processes. We compare XRISM measurements for nine galaxy clusters (Virgo, Perseus, Centaurus, Hydra A, PKS\,0745--19, A2029, Coma, A2319, Ophiuchus) with predictions from three state-of-the-art cosmological simulation suites, TNG-Cluster, The Three Hundred Project GADGET-X, and GIZMO-SIMBA, that employ different models of feedback. In cool cores, XRISM reveals systematically lower velocity dispersions than the simulations predict, with all ten measurements below the median simulated values by a factor on average and all falling within the bottom of the predicted distributions. The observed kinetic-to-total pressure ratio is also lower, with a median value of , compared to the predicted for the three simulations. Outside the cool cores and in non-cool-core clusters, simulations show better agreement with XRISM measurements, except for the outskirts of the relaxed, cool-core cluster A2029, which exhibits an exceptionally low kinetic pressure support (), with none of the simulated systems in either of the three suites reaching such low levels. The non-cool-core Coma and A2319 exhibit dispersions at the lower end but within the simulated spread. Our comparison suggests that the three numerical models may overestimate the kinetic effects of SMBH feedback in cluster cores. Additional XRISM observations of non-cool-core clusters will clarify if there is a systematic tension in the gravity-dominated regime as well.
Keywords
Cite
@article{arxiv.2510.06322,
title = {Comparing XRISM cluster velocity dispersions with predictions from cosmological simulations: are feedback models too ejective?},
author = {XRISM Collaboration and Marc Audard and Hisamitsu Awaki and Ralf Ballhausen and Aya Bamba and Ehud Behar and Rozenn Boissay-Malaquin and Laura Brenneman and Gregory V. Brown and Lia Corrales and Elisa Costantini and Renata Cumbee and Maria Diaz Trigo and Chris Done and Tadayasu Dotani and Ken Ebisawa and Megan E. Eckart and Dominique Eckert and Satoshi Eguchi and Teruaki Enoto and Yuichiro Ezoe and Adam Foster and Ryuichi Fujimoto and Yutaka Fujita and Yasushi Fukazawa and Kotaro Fukushima and Akihiro Furuzawa and Luigi Gallo and Javier A. García and Liyi Gu and Matteo Guainazzi and Kouichi Hagino and Kenji Hamaguchi and Isamu Hatsukade and Katsuhiro Hayashi and Takayuki Hayashi and Natalie Hell and Edmund Hodges-Kluck and Ann Hornschemeier and Yuto Ichinohe and Daiki Ishi and Manabu Ishida and Kumi Ishikawa and Yoshitaka Ishisaki and Jelle Kaastra and Timothy Kallman and Erin Kara and Satoru Katsuda and Yoshiaki Kanemaru and Richard Kelley and Caroline Kilbourne and Shunji Kitamoto and Shogo Kobayashi and Takayoshi Kohmura and Aya Kubota and Maurice Leutenegger and Michael Loewenstein and Yoshitomo Maeda and Maxim Markevitch and Hironori Matsumoto and Kyoko Matsushita and Dan McCammon and Brian McNamara and François Mernier and Eric D. Miller and Jon M. Miller and Ikuyuki Mitsuishi and Misaki Mizumoto and Tsunefumi Mizuno and Koji Mori and Koji Mukai and Hiroshi Murakami and Richard Mushotzky and Hiroshi Nakajima and Kazuhiro Nakazawa and Jan-Uwe Ness and Kumiko Nobukawa and Masayoshi Nobukawa and Hirofumi Noda and Hirokazu Odaka and Shoji Ogawa and Anna Ogorzałek and Takashi Okajima and Naomi Ota and Stephane Paltani and Robert Petre and Paul Plucinsky and Frederick S. Porter and Katja Pottschmidt and Kosuke Sato and Toshiki Sato and Makoto Sawada and Hiromi Seta and Megumi Shidatsu and Aurora Simionescu and Randall Smith and Hiromasa Suzuki and Andrew Szymkowiak and Hiromitsu Takahashi and Mai Takeo and Toru Tamagawa and Keisuke Tamura and Takaaki Tanaka and Atsushi Tanimoto and Makoto Tashiro and Yukikatsu Terada and Yuichi Terashima and Yohko Tsuboi and Masahiro Tsujimoto and Hiroshi Tsunemi and Takeshi Tsuru and Aysegül Tümer and Hiroyuki Uchida and Nagomi Uchida and Yuusuke Uchida and Hideki Uchiyama and Shutaro Ueda and Yoshihiro Ueda and Shinichiro Uno and Jacco Vink and Shin Watanabe and Brian J. Williams and Satoshi Yamada and Shinya Yamada and Hiroya Yamaguchi and Kazutaka Yamaoka and Noriko Yamasaki and Makoto Yamauchi and Shigeo Yamauchi and Tahir Yaqoob and Tomokage Yoneyama and Tessei Yoshida and Mihoko Yukita and Irina Zhuravleva and Weiguang Cui and Stefano Ettori and Skylar Grayson and Annie Heinrich and Hannah McCall and Dylan Nelson and Nobuhiro Okabe and Yuki Omiya and Arnab Sarkar and Evan Scannapieco and Ming Sun and Keita Tanaka and Nhut Truong and Daniel R. Wik and Congyao Zhang and John ZuHone},
journal= {arXiv preprint arXiv:2510.06322},
year = {2025}
}
Comments
Accepted for publication in ApJ Letters