Chlorine and potassium enrichment in the Cassiopeia A supernova remnant

The elements in the Universe are synthesized primarily in stars and supernovae, where nuclear fusion favours the production of even-Z elements. In contrast, odd-Z elements are less abundant and their yields are highly dependent on detailed stellar physics, making theoretical predictions of their cosmic abundance uncertain. In particular, the origin of odd-Z elements such as phosphorus (P), chlorine (Cl) and potassium (K), which are important for planet formation and life, is poorly understood. While the abundances of these elements in Milky Way stars are close to solar values, supernova explosion models systematically underestimate their production by up to an order of magnitude, indicating that key mechanisms for odd-Z nucleosynthesis are currently missing from theoretical models. Here we report the observation of P, Cl and K in the Cassiopeia A supernova remnant using high-resolution X-ray spectroscopy with X-Ray Imaging and Spectroscopy Mission data, with the detection of K at above the 6σ level being the most significant finding. Supernova explosion models of normal massive stars cannot explain the element abundance pattern, especially the high abundances of Cl and K, while models that include stellar rotation, binary interactions or shell mergers agree closely with the observations. Our observations suggest that such stellar activity plays an important role in supplying these elements to the Universe. XRISM observations show the presence of odd-numbered elements chlorine and potassium in Cas A. These findings suggest that stellar activity plays an important role in cosmic chemical evolution, enriching space with elements vital for planets and life.

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Publication Details

Journal
Nature Astronomy
Published
2025-12-04
DOI
https://doi.org/10.1038/s41550-025-02714-4
Citations
1
Primary Topic
Gamma-ray bursts and supernovae
Type
article
Field-Weighted Citation Impact
1.15

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article

Chlorine and potassium enrichment in the Cassiopeia A supernova remnant

Kotaro Fukushima, Lía Corrales, Chris Done, Katsuhiro Hayashi et al.
1 citations
Nature Astronomy
Gamma-ray bursts and supernovae
1.15
article

Chlorine and potassium enrichment in the Cassiopeia A supernova remnant

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

Abstract

The elements in the Universe are synthesized primarily in stars and supernovae, where nuclear fusion favours the production of even-Z elements. In contrast, odd-Z elements are less abundant and their yields are highly dependent on detailed stellar physics, making theoretical predictions of their cosmic abundance uncertain. In particular, the origin of odd-Z elements such as phosphorus (P), chlorine (Cl) and potassium (K), which are important for planet formation and life, is poorly understood. While the abundances of these elements in Milky Way stars are close to solar values, supernova explosion models systematically underestimate their production by up to an order of magnitude, indicating that key mechanisms for odd-Z nucleosynthesis are currently missing from theoretical models. Here we report the observation of P, Cl and K in the Cassiopeia A supernova remnant using high-resolution X-ray spectroscopy with X-Ray Imaging and Spectroscopy Mission data, with the detection of K at above the 6σ level being the most significant finding. Supernova explosion models of normal massive stars cannot explain the element abundance pattern, especially the high abundances of Cl and K, while models that include stellar rotation, binary interactions or shell mergers agree closely with the observations. Our observations suggest that such stellar activity plays an important role in supplying these elements to the Universe. XRISM observations show the presence of odd-numbered elements chlorine and potassium in Cas A. These findings suggest that stellar activity plays an important role in cosmic chemical evolution, enriching space with elements vital for planets and life.

Nature AstronomyVol. 10(1)
Tohoku Institute of Technology (JP), 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), Lawrence Livermore National Laboratory (US), Shizuoka University (JP), Goddard Space Flight Center (US), Rikkyo University (JP), University of Wisconsin–Madison (US), High Energy Accelerator Research Organization (JP), Johns Hopkins University (US), Fujita Health University (JP), 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), Durham University (GB), Tohoku University (JP), Kanto Gakuin University (JP), Kyoto University (JP), University of Michigan (US), University of Teacher Education Fukuoka (JP), Japan Aerospace Exploration Agency (JP), National Institute of Technology, Kumamoto College (JP), Tohoku Gakuin University (JP), Yale University (US), University of Chicago (US), European Space Astronomy Centre (ES), Osaka Health Science University (JP), Center for Astrophysics Harvard & Smithsonian (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, State Tobacco Monopoly Administration, 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%
Gamma-ray bursts and supernovae
1.15
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