High Metallicity of the X-Ray Gas Up to the Virial Radius of a Binary Cluster of Galaxies: Evidence of Galactic Superwinds at High-Redshift
High Metallicity of the X-Ray Gas Up to the Virial Radius of a Binary Cluster of Galaxies: Evidence of Galactic Superwinds at High-Redshift
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DOI：
10.1093/pasj/60.sp1.s343
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发表时间：
2007-05
影响因子：
2.3
通讯作者：
Y. Fujita;N. Tawa;K. Hayashida;M. Takizawa;H. Matsumoto;N. Okabe;T. Reiprich
中科院分区：
文献类型：
--
作者：
Y. Fujita;N. Tawa;K. Hayashida;M. Takizawa;H. Matsumoto;N. Okabe;T. Reiprich
我们提出了一个分析的朱雀观测星系团A399和A401之间的链接区域。首次获得了团簇维里半径范围内团簇内介质的金属丰度。我们确定的金属量的维里半径的两个集群相互交叉（~2 Mpc远离他们的中心），并发现它是可比的，在他们的内部区域（~0.2 Zsun）。直到维里半径的金属丰度均匀性不太可能是由于团簇碰撞引起的混合造成的。由于冲压压力太小，无法剥离星系团维里半径周围的星际介质，我们在那里发现的相当高的金属丰度表明ICM中的金属不是通过冲压压力剥离从成员星系中传输出来的。相反，这种均匀性表明，在星系团形成之前，原星系团区域被来自星系的极其强大的外流（超级风）广泛地污染了金属。我们还寻找了该区域温暖炽热的星系际介质中的氧辐射，并得到了氢密度的严格上限（nH<4.1 × 10 ^-5 cm^-3）。
We present an analysis of a Suzaku observation of the link region between the galaxy clusters A399 and A401. We obtained the metallicity of the intracluster medium (ICM) up to the cluster virial radii for the first time. We determine the metallicity where the virial radii of the two clusters cross each other (~2 Mpc away from their centers) and found that it is comparable to that in their inner regions (~0.2 Zsun). It is unlikely that the uniformity of metallicity up to the virial radii is due to mixing caused by a cluster collision. Since the ram-pressure is too small to strip the interstellar medium of galaxies around the virial radius of a cluster, the fairly high metallicity that we found there indicates that the metals in the ICM are not transported from member galaxies by ram-pressure stripping. Instead, the uniformity suggests that the proto-cluster region was extensively polluted with metals by extremely powerful outflows (superwinds) from galaxies before the clusters formed. We also searched for the oxygen emission from the warm--hot intergalactic medium in that region and obtained a strict upper limit of the hydrogen density (nH<4.1x10^-5 cm^-3).