Overionized plasma in the supernova remnant Sagittarius A East anchored by XRISM observations

Abstract Sagittarius A East is a supernova remnant with a unique surrounding environment, as it is located in the immediate vicinity of the supermassive black hole at the Galactic center, Sagittarius A$^{*}$. The X-ray emission of the remnant is suspected to show features of overionized plasma, which would require peculiar evolutionary paths. We report on the first observation of Sagittarius A East with the X-Ray Imaging and Spectroscopy Mission (XRISM). Equipped with a combination of a high-resolution microcalorimeter spectrometer and a large field-of-view CCD imager, we for the first time resolved the Fe xxv K-shell lines into fine structure lines and measured the forbidden-to-resonance intensity ratio to be $1.39 \pm 0.12$, which strongly suggests the presence of overionized plasma. We obtained a reliable constraint on the ionization temperature just before the transition into the overionization state, of $\gt\! 4\:$keV. The recombination timescale was constrained to be $\lt\! 8 \times 10^{11} \:$cm$^{-3}\:$s. The small velocity dispersion of $109 \pm 6\:$km$\:$s$^{-1}$ indicates a low Fe ion temperature $\lt\! 8\:$keV and a small expansion velocity $\lt\! 200\:$km$\:$s$^{-1}$. The high initial ionization temperature and small recombination timescale suggest that either rapid cooling of the plasma via adiabatic expansion from dense circumstellar material or intense photoionization by Sagittarius A$^{*}$ in the past may have triggered the overionization.

Authors

Institutions

Publication Details

Journal
Publications of the Astronomical Society of Japan
Published
2024-12-03
DOI
https://doi.org/10.1093/pasj/psae111
Citations
6
Primary Topic
Astrophysical Phenomena and Observations
Type
article
Field-Weighted Citation Impact
1.99

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

Overionized plasma in the supernova remnant Sagittarius A East anchored by XRISM observations

Lía Corrales, Chris Done, Katsuhiro Hayashi, Aya Kubota et al.
6 citations
Publications of the Astronomical Society of Japan
Astrophysical Phenomena and Observations
1.99
article

Overionized plasma in the supernova remnant Sagittarius A East anchored by XRISM observations

Lía Corrales, Chris Done, Katsuhiro Hayashi, Aya Kubota, Kyoko Matsushita, Kouichi Hagino, M. Shidatsu, M. Audard, J. S. Kaastra, Paul P. Plucinsky, Yuken Ohshiro, Erin Kara, S. Eguchi, Hirokazu Odaka, Luigi Gallo, Hideki Uchiyama, Hirofumi Noda, Hisamitsu Awaki, Y. Terada, K. Mukai, María Díaz Trigo, Aya Bamba, Eric D. Miller, Yoshiaki Kanemaru, J. M. Mïller, Ryuichi Fujimoto, Satoshi Yamada, Yutaka Fujita, Javier A. García, Kenji Hamaguchi, T. R. Kallman, Anna Ogorzałek, A. Simionescu, Megan E. Eckart, S. Paltani, Edmund Hodges‐Kluck, Renata Cumbee, Takuto Narita, Hiroyuki Uchida, Hironori Matsumoto, A. E. Hornschemeier, Irina Zhuravleva, Mai Takeo, Gregory V. Brown, Adam Foster, Laura Brenneman, Masahiro Tsujimoto, Yoshitomo Maeda, Liyi Gu, Noriko Y. Yamasaki, D. McCammon, Toru Tamagawa, Shōgo Kobayashi, K. Yamaoka, Jan‐Uwe Ness, Kojiro Tanaka, Yuki Amano, Michael Loewenstein, Hiromasa Suzuki, Naomi Ota, M. Guainazzi, Kosuke Sato, M. Balakrishnan, Takaaki Tanaka, Satoru Katsuda, Tsunefumi Mizuno, Randall K. Smith, Robert Petre, M. Yamauchi, Ikuyuki Mitsuishi, Teruaki Enoto, Takeshi Go Tsuru, Isamu Hatsukade, Hiroshi Murakami, Ken Ebisawa, Maurice A. Leutenegger, Takashi Okajima, Q. Daniel Wang, F. S. Porter, D. Eckert, Maxim Markevitch, R. F. Mushotzky, Natalie Hell, Kumiko Nobukawa, Takayuki Hayashi, Ralf Ballhausen, Mihoko Yukita, B. R. McNamara, Masayoshi Nobukawa, Misaki Mizumoto, Rozenn Boissay-Malaquin, François Mernier, Shunji Kitamoto, T. Yoneyama, Shin Watanabe, Toshiki Sato, E. Costantini, H. Takahashi, S. Yamada, Yuusuke Uchida, Yuto Ichinohe, A. Tanimoto, Caroline A. Kilbourne, Shoji Ogawa, Nagomi Uchida, Yohko Tsuboi, Yuma Aoki, Koji Mori, Ehud Behar, Katja Pottschmidt, Shinichiro Uno, Yoshihiro Ueda, Kumi Ishikawa, Hiromi Seta, Hiroshi Nakajima, Hiroya Yamaguchi, Richard L. Kelley, Hiroshi Tsunemi, Jacco Vink, Yuichi Terashima, Akihiro Furuzawa, Yuichiro Ezoe, Makoto Sawada, Keisuke Tamura, M. Ishida, Tessei Yoshida, Yoshitaka Ishisaki, Yasushi Fukazawa, Takayoshi Kohmura, Kazuhiro Nakazawa, Andrew Szymkowiak, Tadayasu Dotani, Anje Yoshimoto, Kotaro Fukushima, Makoto Tashiro, Shigeo Yamauchi, Tahir Yaqoob, Brian J. Williams
article en
6 citations

Abstract

Abstract Sagittarius A East is a supernova remnant with a unique surrounding environment, as it is located in the immediate vicinity of the supermassive black hole at the Galactic center, Sagittarius A$^{*}$. The X-ray emission of the remnant is suspected to show features of overionized plasma, which would require peculiar evolutionary paths. We report on the first observation of Sagittarius A East with the X-Ray Imaging and Spectroscopy Mission (XRISM). Equipped with a combination of a high-resolution microcalorimeter spectrometer and a large field-of-view CCD imager, we for the first time resolved the Fe xxv K-shell lines into fine structure lines and measured the forbidden-to-resonance intensity ratio to be $1.39 \pm 0.12$, which strongly suggests the presence of overionized plasma. We obtained a reliable constraint on the ionization temperature just before the transition into the overionization state, of $\gt\! 4\:$keV. The recombination timescale was constrained to be $\lt\! 8 \times 10^{11} \:$cm$^{-3}\:$s. The small velocity dispersion of $109 \pm 6\:$km$\:$s$^{-1}$ indicates a low Fe ion temperature $\lt\! 8\:$keV and a small expansion velocity $\lt\! 200\:$km$\:$s$^{-1}$. The high initial ionization temperature and small recombination timescale suggest that either rapid cooling of the plasma via adiabatic expansion from dense circumstellar material or intense photoionization by Sagittarius A$^{*}$ in the past may have triggered the overionization.

Publications of the Astronomical Society of JapanVol. 77(1)
Kagoshima University (JP), Hiroshima University (JP), University of Geneva (CH), University of Miyazaki (JP), Kumamoto Gakuen University (JP), Leiden University (NL), California Institute of Technology (US), Nihon Fukushi University (JP), Vassar College (US), Lawrence Livermore National Laboratory (US), Shizuoka University (JP), Goddard Space Flight Center (US), Rikkyo University (JP), University of Wisconsin–Madison (US), Pioneer (United States) (US), Johns Hopkins University (US), Nara University of Education (JP), University of Waterloo (CA), Konan University (JP), Tokyo University of Science (JP), Meiji University (JP), Shibaura Institute of Technology (JP), Technion – Israel Institute of Technology (IL), Amherst College (US), Durham University (GB), Tohoku University (JP), Kanto Gakuin University (JP), Kyoto University (JP), University of Massachusetts Amherst (US), University of Michigan (US), University of Teacher Education Fukuoka (JP), Japan Aerospace Exploration Agency (JP), European Space Agency (FR), Yale Cancer Center (US), Tohoku Gakuin University (JP), Yale University (US), University of Chicago (US), European Space Astronomy Centre (ES), Pioneer (Japan) (JP), RIKEN (JP), Center for Astrophysics Harvard & Smithsonian (US), Fujita Health University Hospital (JP), Astrophysics Science Division (US), Institute of Space and Astronautical Science (JP), RIKEN Nishina Center (JP), Ehime University (JP), Leiden Observatory, European Space Research and Technology Centre (NL), Space Research Organisation Netherlands (NL), Nagoya University (JP), Massachusetts Institute of Technology (US), Saint Mary's University (CA), University of Maryland, College Park (US), Tokyo Metropolitan University (JP), Saitama University (JP), The University of Tokyo (JP), University of Maryland, Baltimore County (US), University of Amsterdam (NL), Kindai University (JP), Chuo University (JP), The University of Osaka (JP), Nara Women's University (JP)
National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, Alfred P. Sloan Foundation, Kagoshima University, Nuclear Safety and Security Commission, Rikkyo University, Goddard Space Flight Center, Canadian Space Agency, Science and Technology Facilities Council, Japan Society for the Promotion of Science, RIKEN, Lawrence Livermore National Laboratory
Openalex Percentile: Top 14%
Astrophysical Phenomena and Observations
1.99
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.