A2125 and Its Environs: Evidence for an X-Ray-emitting Hierarchical Superstructure
A2125 and Its Environs: Evidence for an X-Ray-emitting Hierarchical Superstructure
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A2125 及其周围环境：X 射线发射分层上层结构的证据
DOI：
10.1086/310859
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
R. Brunner
中科院分区：
文献类型：
--
作者：
Q. Wang;A. Connolly;R. Brunner
基于ROSAT/PSPC的深入观测，我们揭示了星系团A2125内部和周围的一个由扩展的X射线发射物体组成的拉长复合体。对野外星系的多色光学成像表明，这个复合体代表了一个红移~0.247处跨越~11h−150MPC的分级超结构。A2125的多峰X射线形态和大的蓝色星系碎片表明，该星系团正在经历亚单位的合并。上层建筑包含两个额外的星系团，预计距离A2125只有3和4.3h−150Mpc。然而，最有趣的特征是，从远离单个星系团的中等集中的星系发出的低表面亮度X射线。正如结构形成的N体/流体模拟所预测的那样，发射可能发生在高温(~107K)的星际介质中。
Based on a deep ROSAT/PSPC observation, we reveal an elongated complex of extended X-ray-emitting objects in and around the galaxy cluster A2125. Multicolor optical imaging of galaxies in the field suggests that this complex represents a hierarchical superstructure spanning ~11 h−150 Mpc at the redshift ~0.247. The multiple peak X-ray morphology and large blue galaxy fraction of A2125 indicate that the cluster is undergoing a coalescence of subunits. The superstructure contains two additional clusters, projected at distances of only 3 and 4.3 h−150 Mpc from A2125. The most interesting feature is, however, the low surface brightness X-ray emission from a moderate galaxy concentration away from individual clusters. The emission likely arises in a hot (~107 K) intergalactic medium, as predicted in N-body/hydro simulations of structure formation.