| アイテムタイプ |
学術雑誌論文 / Journal Article(1) |
| 公開日 |
2025-12-03 |
| タイトル |
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タイトル |
The unusual spectrum of the X-ray transient source XRISM J174610.8-290021 near the Galactic Center |
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言語 |
en |
| 言語 |
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言語 |
eng |
| キーワード |
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言語 |
en |
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キーワード |
Galaxy: center |
| キーワード |
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言語 |
en |
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キーワード |
stars: low-mass |
| キーワード |
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言語 |
en |
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キーワード |
X-rays: binaries |
| キーワード |
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言語 |
en |
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キーワード |
X-rays: stars |
| 資源タイプ |
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資源タイプ |
journal article |
| アクセス権 |
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アクセス権 |
open access |
| 著者 |
Yoshimoto, Anje
Yamauchi, Shigeo
Nobukawa, Masayoshi
Uchiyama, Hideki
Nobukawa, Kumiko K.
Aoki, Yuma
Ishida, Manabu
| en |
Ishida, Manabu（Personal）
JAXA Institute of Space and Astronautical Science
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Search repository
Kanemaru, Yoshiaki
| en |
Kanemaru, Yoshiaki（Personal）
JAXA Institute of Space and Astronautical Science
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Search repository
Shidatsu, Megumi
Hayashi, Takayuki
| en |
Hayashi, Takayuki（Personal）
University of Maryland, Baltimore County (UMBC)
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Search repository
Maeda, Yoshitomo
| en |
Maeda, Yoshitomo（Personal）
JAXA Institute of Space and Astronautical Science
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Search repository
Matsumoto, Hironori
Tsuboi, Yohko
鈴木, 寛大
WEKO
35601
e-Rad_Researcher
50915402
| ja |
鈴木, 寛大
宮崎大学
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| ja-Kana |
スズキ, ヒロマサ
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| en |
Suzuki, Hiromasa
University of Miyazaki
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Search repository
Nakajima, Hiroshi
Wang, Q. Daniel
Eguchi, Satoshi
Yoneyama, Tomokage
Dotani, Tadayasu
| en |
Dotani, Tadayasu（Personal）
JAXA Institute of Space and Astronautical Science
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Search repository
Behar, Ehud
Terada, Yukikatsu
| en |
Terada, Yukikatsu（Personal）
JAXA Institute of Space and Astronautical Science
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Search repository
Suzuki, Nari
Yoshimoto, Marina
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| 抄録 |
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内容記述タイプ |
Abstract |
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内容記述 |
The Galactic Center region was observed with the X-Ray Imaging and Spectroscopy Mission (XRISM) X-ray observatory during the performance verification phase in 2024 and a point-like X-ray source was detected with the X-ray imager Xtend at a position of (α, δ)J2000.0 =(17h46m10s8, -29000′21″), which is thus named XRISM J174610.8-290021. This source was bright in February to March and showed time variations in count rate by more than one order of magnitude in one week. The 2–10keV X-ray luminosity was ∼1035 erg s−1 for the assumed distance of 8kpc. However, after six months, it was below the detection limit. We found a hint of periodicity of 1537s from timing analysis. The XRISM/Xtend spectrum has emission lines from helium-like iron (Fexxv–Heα) at 6.7keV and hydrogen-like iron (Fexxvi–Lyα) at 6.97keV; their intensity ratio is unusual with the latter being four times stronger than the former. If the emission is of thermal origin, the ionization temperature estimated from the iron-line intensity ratio is ∼30keV, which is inconsistent with the electron temperature estimated from the thermal bremsstrahlung, ∼7keV. Spectral models of magnetic cataclysmic variables, which are often seen in the Galactic Center in this luminosity range, are found to fail to reproduce the obtained spectrum. By contrast, we found that the spectrum is well reproduced with the models of low-mass X-ray binaries containing a neutron star plus two narrow Gaussian lines. We consider that the source is intrinsically bright reaching 1037 ergs-1, but is blocked from direct view due to a high inclination and only the scattered emission is visible. The photo-ionized plasma above the accretion disk with an ionization parameter of ∼105 may explain the unusual iron line ratio. We further discuss the potential contribution of point sources of the type of XRISM J174610.8-290021 to the diffuse Galactic Center X-ray emission. |
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言語 |
en |
| 書誌情報 |
en : Publications of the Astronomical Society of Japan
巻 77,
号 Issue Supplement_1,
p. 96-106,
発行日 2025-06-17
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| 出版者 |
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出版者 |
Oxford University Press (OUP) |
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言語 |
en |
| ISSN |
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収録物識別子タイプ |
EISSN |
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収録物識別子 |
2053051X |
| ISSN |
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収録物識別子タイプ |
ISSN |
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収録物識別子 |
00046264 |
| DOI |
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関連タイプ |
isVersionOf |
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識別子タイプ |
DOI |
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関連識別子 |
https://doi.org/10.1093/pasj/psaf063 |
| 著者版フラグ |
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出版タイプ |
VoR |
fulltext (1.7 MB)
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