Journal article
Astrophysical Journal Letters, 2025
APA
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Audard, M., Awaki, H., Ballhausen, R., Bamba, A., Behar, E., Boissay-Malaquin, R., … Zhang, C. (2025). XRISM Constraints on Unidentified X-Ray Emission Lines, Including the 3.5 keV Line, in the Stacked Spectrum of 10 Galaxy Clusters. 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 Constraints on Unidentified X-Ray Emission Lines, Including the 3.5 KeV Line, in the Stacked Spectrum of 10 Galaxy Clusters.” Astrophysical Journal Letters (2025).
MLA
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Audard, M., et al. “XRISM Constraints on Unidentified X-Ray Emission Lines, Including the 3.5 KeV Line, in the Stacked Spectrum of 10 Galaxy Clusters.” Astrophysical Journal Letters, 2025.
BibTeX Click to copy
@article{m2025a,
title = {XRISM Constraints on Unidentified X-Ray Emission Lines, Including the 3.5 keV Line, in the Stacked Spectrum of 10 Galaxy Clusters},
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, Yasushi 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 Ishi, D. 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, Yoshitomo 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, Hirofumi 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 Tümer, Ayşegül and Uchida, Hiroyuki and Uchida, N. and Uchida, Y. and Uchiyama, H. and Ueda, S. 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 Breuer, J. and Chakraborty, Priyanka and Ettori, S. and Fabian, A. and Heinrich, Annie and Kondo, Marie and Hlavacek-Larrondo, J. and McCall, H. and Nulsen, P. and Rose, T. and Russell, H. and Sarkar, Arnab and Scannapieco, Evan and Suda, Kazunori and Sun, Ming and Tamhane, P. and Truong, N. and Werner, N. and Zhang, Congyao}
}
We stack 3.75 Ms of early XRISM Resolve observations of 10 galaxy clusters to search for unidentified spectral lines in the E = 2.5–15 keV band (rest frame), including the E = 3.5 keV line reported in earlier low spectral resolution studies of cluster samples. Such an emission line may originate from the decay of the sterile neutrino, a warm dark matter (DM) candidate. No unidentified lines are detected in our stacked cluster spectrum, with the 3σ upper limit on the ms ∼ 7.1 keV DM particle decay rate (which corresponds to an E = 3.55 keV emission line) of Γ ∼ 1.0 × 10−27 s−1. This upper limit is 3–4 times lower than the one derived by Hitomi Collaboration from the Perseus observation but still 5 times higher than the XMM-Newton detection reported by E. Bulbul et al. in the stacked cluster sample. XRISM Resolve, with its high spectral resolution but small field of view, may reach the sensitivity needed to test the XMM-Newton cluster sample detection by combining several years worth of future cluster observations.