X-Raying A2125: A Large-Scale Hierarchical Complex of Galaxies and Hot Gas
X-Raying A2125: A Large-Scale Hierarchical Complex of Galaxies and Hot Gas
复制标题
X 射线 A2125：星系和热气体的大规模分层复合体
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
M. Ledlow
中科院分区：
文献类型：
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作者：
Q. Wang;F. Owen;M. Ledlow
我们提出了一个82 KS钱德拉ACIS-I观测一个大规模的层次复杂，其中包括各种集群/星系群和低表面亮度X射线发射在z = 0.247。这种高分辨率的钱德拉观测使我们第一次能够明确地将X射线贡献从离散源和大规模扩散热气体中分离出来。我们在17′ × 17′视场内探测到99个X射线源。其中10个来源被确定为复合体的成员，大多是射电明亮。虽然未解析的X射线源往往与中等密度环境中的星系有关，但扩展的X射线发射峰值位于中央星系团的明亮射电星系。特别是，在快速移动的星系C153的一侧出现了明显的X射线轨迹，这显然是由于冲压压力剥离造成的。来自中央星系团的漫X射线发射可以用特征温度为3.2 keV、重元素丰度为0.24太阳能（90%置信度不确定性）的热等离子体来表征。相比之下，低表面亮度的X射线辐射补丁显然起源于相对低密度的星系际气体，特征温度为0.98 keV，丰度为10.09太阳能。钱德拉的观测以及大量的多波长数据表明，该复合体代表了几个星系子结构的投影，这些子结构可能正在经历重大合并。我们讨论了复杂的动力学状态及其子结构，以及X射线发射星系的性质及其与环境的关系。
We present an 82 ks Chandra ACIS-I observation of a large-scale hierarchical complex, which consists of various clusters/groups of galaxies and low surface brightness X-ray emission at z = 0.247. This high-resolution Chandra observation allows us for the first time to separate unambiguously the X-ray contributions from discrete sources and large-scale diffuse hot gas. We detect 99 X-ray sources in a 17′ × 17′ field. Ten of these sources are identified as members of the complex and are mostly radio-bright. Whereas unresolved X-ray sources tend to be associated with galaxies in intermediate density environments, extended X-ray emission peak at bright radio galaxies in the central cluster. In particular, a distinct X-ray trail appears on one side of the fast-moving galaxy C153, clearly due to ram pressure stripping. The diffuse X-ray emission from the central cluster can be characterized by a thermal plasma with a characteristic temperature of 3.2 keV and a heavy element abundance of 0.24 solar (90% confidence uncertainties). In comparison, a patch of low surface brightness X-ray emission apparently originates in relatively low density intergalactic gas with a characteristic temperature of 0.98 keV and an abundance of ≲0.09 solar. The Chandra observation, together with extensive multiwavelength data, indicates that the complex represents a projection of several galaxy substructures, which may be undergoing major mergers. We discuss the dynamic states of the complex and its substructures, as well as properties of X-ray-emitting galaxies and the relationship to their environments.