Journal article
Astrophysical Journal Letters, 2025
APA
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Audard, M., Awaki, H., Ballhausen, R., Bamba, A., Behar, E., Boissay-Malaquin, R., … Tamhane, P. (2025). XRISM Reveals Low Nonthermal Pressure in the Core of the Hot, Relaxed Galaxy Cluster A2029. Astrophysical Journal Letters.
Chicago/Turabian
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Audard, M., H. Awaki, R. Ballhausen, A. Bamba, E. Behar, R. Boissay-Malaquin, L. Brenneman, et al. “XRISM Reveals Low Nonthermal Pressure in the Core of the Hot, Relaxed Galaxy Cluster A2029.” Astrophysical Journal Letters (2025).
MLA
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Audard, M., et al. “XRISM Reveals Low Nonthermal Pressure in the Core of the Hot, Relaxed Galaxy Cluster A2029.” Astrophysical Journal Letters, 2025.
BibTeX Click to copy
@article{m2025a,
title = {XRISM Reveals Low Nonthermal Pressure in the Core of the Hot, Relaxed Galaxy Cluster A2029},
year = {2025},
journal = {Astrophysical Journal Letters},
author = {Audard, M. and Awaki, H. and Ballhausen, R. and Bamba, A. and Behar, E. and Boissay-Malaquin, R. and Brenneman, L. and Brown, G. V. and Corrales, Lia and Costantini, E. and Cumbee, R. and Trigo, M. Díaz and Done, C. and Dotani, T. and Ebisawa, K. and Eckart, M. and Eckert, Dominique and Eguchi, Satoshi and Enoto, T. and Ezoe, Y. and Foster, A. and Fujimoto, R. and Fujita, Y. and Fukazawa, Y. and Fukushima, Kotaro and Furuzawa, A. and Gallo, L. and García, Javier A. and Gu, Liyi and Guainazzi, M. and Hagino, Kouichi and Hamaguchi, Kenji and Hatsukade, I. and Hayashi, K. and Hayashi, T. and Hell, N. and Hodges-Kluck, E. and Hornschemeier, A. and Ichinohe, Y. and Ishida, Manabu and Ishikawa, K. and Ishisaki, Y. and Kaastra, J. and Kallman, T. and Kara, Erin and Katsuda, S. and Kanemaru, Y. and Kelley, Rich and Kilbourne, C. and Kitamoto, S. and Kobayashi, S. and Kohmura, T. and Kubota, A. and Leutenegger, M. and Loewenstein, M. and Maeda, Y. and Markevitch, M. and Matsumoto, Hironori and Matsushita, K. and McCammon, D. and McNamara, Brian and Mernier, F. and Miller, E. and Miller, Jon M. and Mitsuishi, I. and Mizumoto, M. and Mizuno, T. and Mori, K. and Mukai, K. and Murakami, Hiroshi and Mushotzky, R. and Nakajima, H. and Nakazawa, K. and Ness, J. and Nobukawa, K. and Nobukawa, M. and Noda, H. and Odaka, H. and Ogawa, S. and Ogorzałek, A. and Okajima, T. and Ota, Naomi and Paltani, S. and Petre, R. and Plucinsky, P. and Porter, F. and Pottschmidt, K. and Sato, Kosuke and Sato, Toshiki and Sawada, M. and Seta, H. and Shidatsu, M. and Simionescu, A. and Smith, Randall K. and Suzuki, Hiromasa and Szymkowiak, A. and Takahashi, H. and Takeo, M. and Tamagawa, T. and Tamura, Keisuke and Tanaka, Takaaki and Tanimoto, A. and Tashiro, M. and Terada, Y. and Terashima, Y. and Tsuboi, Y. and Tsujimoto, M. and Tsunemi, H. and Tsuru, T. and Uchida, Hiroyuki and Uchida, N. and Uchida, Y. and Uchiyama, H. and Ueda, Y. and Uno, S. and Vink, J. and Watanabe, S. and Williams, Brian J. and Yamada, S. and Yamada, S. and Yamaguchi, Hiroya and Yamaoka, K. and Yamasaki, N. and Yamauchi, M. and Yamauchi, S. and Yaqoob, T. and Yoneyama, T. and Yoshida, Tessei and Yukita, M. and Zhuravleva, I. and Bartalesi, T. and Ettori, S. and Kosarzycki, Roman and Lovisari, L. and Rose, T. and Sarkar, Arnab and Sun, Ming and Tamhane, P.}
}
We present XRISM Resolve observations of the core of the hot, relaxed galaxy cluster Abell 2029 (A2029). We find that the line-of-sight bulk velocity of the intracluster medium (ICM) within the central 180 kpc is at rest with respect to the brightest cluster galaxy, with a 3σ upper limit of ∣vbulk∣ < 100 km s−1. We robustly measure the field-integrated ICM velocity dispersion to be σv = 169 ± 10 km s−1, obtaining similar results for both single-temperature and two-temperature plasma models to account for the cluster cool core. This result, if ascribed to isotropic turbulence, implies a subsonic ICM with Mach number M3D≈0.22 and a nonthermal pressure fraction of 2.6 ± 0.3%. The turbulent velocity is similar to what was measured in the core of the Perseus cluster by Hitomi, but here in a more massive cluster with an ICM temperature of 7 keV, the limit on the nonthermal pressure fraction is even more stringent. Our result is consistent with expectations from simulations of relaxed clusters, but it is on the low end of the predicted distribution, indicating that A2029 is an exceptionally relaxed cluster with no significant impacts from either a recent minor merger or active galactic nucleus activity.