SUZAKU OBSERVATIONS OF SUBHALOS IN THE COMA CLUSTER

The Astrophysical Journal 806 巻 1 号 123- 頁 2015-06-10 発行
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タイトル ( eng )
SUZAKU OBSERVATIONS OF SUBHALOS IN THE COMA CLUSTER
作成者
Sasaki Toru
Matsushita Kyoko
Sato Kosuke
収録物名
The Astrophysical Journal
806
1
開始ページ 123
抄録
We observed three massive subhalos in the Coma cluster with Suzaku. These subhalos, labeled “ID 1,” “ID 2,” and “ID 32,” were detected with a weak-lensing survey using Subaru/Suprime-Cam, and are located at the projected distances of 1.4 r_500, 1.2 r_500, and 1.6 r_500 from the center of the Coma cluster, respectively. The subhalo “ID 1” has a compact X-ray excess emission close to the center of the weak-lensing mass contour, and the gas mass to weak-lensing mass ratio is about 0.001. The temperature of the emission is about 3 keV, which is slightly lower than that of the surrounding intracluster medium (ICM) and that expected for the temperature versus mass relation of clusters of galaxies. The subhalo “ID 32” shows an excess emission whose peak is shifted toward the opposite direction from the center of the Coma cluster. The gas mass to weak-lensing mass ratio is also about 0.001, which is significantly smaller than regular galaxy groups. The temperature of the excess is about 0.5 keV and significantly lower than that of the surrounding ICM and far from the temperature versus mass relation of clusters. However, there is no significant excess X-ray emission in the “ID 2” subhalo. Assuming an infall velocity of about 2000 km s^−1, at the border of the excess X-ray emission, the ram pressures for “ID 1” and “ID 32” are comparable to the gravitational restoring force per area. We also studied the effect of the Kelvin–Helmholtz instability to strip the gas. Although we found X-ray clumps associated with the weak-lensing subhalos, their X-ray luminosities are much lower than the total ICM luminosity in the cluster outskirts.
著者キーワード
galaxies: clusters: individual (Coma Cluster) – X-rays: galaxies: clusters
内容記述
We acknowledge the support of a Grant-in-Aid for Scientific Research from the MEXT, No. 25400235 (K.M.), 25800112 (K.S.), and 26800097 (N.O.). This work was supported by “World Premier International Research Center Initiative (WPI Initiative)” and the Funds for the Development of Human Resources in Science and Technology under MEXT, Japan.
NDC分類
天文学・宇宙科学 [ 440 ]
言語
英語
資源タイプ 学術雑誌論文
出版者
IOP Publishing
発行日 2015-06-10
権利情報
© 2015. The American Astronomical Society. All rights reserved.
出版タイプ Version of Record(出版社版。早期公開を含む)
アクセス権 オープンアクセス
収録物識別子
[ISSN] 0004-637X
[ISSN] 1538-4357
[NCID] AA00553253
[DOI] 10.1088/0004-637X/806/1/123
[DOI] https://doi.org/10.1088/0004-637X/806/1/123