ABELL 1201: THE ANATOMY OF A COLD FRONT CLUSTER FROM COMBINED OPTICAL AND X-RAY DATA
ABELL 1201: THE ANATOMY OF A COLD FRONT CLUSTER FROM COMBINED OPTICAL AND X-RAY DATA
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ABELL 1201：结合光学和 X 射线数据对冷锋团簇进行剖析
DOI：
10.1088/0004-637x/692/1/702
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
G. Poole
中科院分区：
文献类型：
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作者：
M. Owers;P. Nulsen;W. Couch;M. Markevitch;G. Poole
本文利用3.9m英澳望远镜和6.5m多镜望远镜的Chandra资料和多目标光谱资料，对冷锋星团Abell1201进行了X射线和光学联合分析。本文是从钱德拉档案中选取的冷锋星团样本的系列研究的第一篇，目的是将冷锋与合并活动联系起来，了解合并的动力及其对星系团组成的影响。阿贝尔1201的钱德拉X射线图像显示了两个明显的表面亮度不连续，显示为冷锋和残余的核心结构。温度图显示了一个复杂的多相温度结构，热气体区域点缀着冷气体指状物。我们的光学分析是基于321个确认成员的样本，其平均红移为0.1673±0.0002，速度色散为778±36 Km S−1。我们寻找动力子结构，并找到与银河系表面密度相一致的多个局域速度子结构的明确证据。最值得注意的是，我们发现该结构与残留的X射线核心相吻合。尽管有明确的动力活动证据，我们发现特殊的速度分布并没有明显偏离高斯分布。我们应用二体动力学分析来评估哪些子结构是绑定的，因此在集群合并历史方面具有动态重要性。我们认为，阿贝尔1201中的冷锋是它与一个较小的亚单位合并的结果，它诱导了气体运动，从而产生了“晃动的”冷锋。Abell 1201示出了当试图确定集群的动态状态时组合多波长数据和多个子结构检测技术的价值。
We present a combined X-ray and optical analysis of the cold front cluster Abell 1201 using archival Chandra data and multi-object spectroscopy taken with the 3.9 m Anglo-Australian and 6.5 m Multiple Mirror Telescopes. This paper represents the first in a series presenting a study of a sample of cold front clusters selected from the Chandra archives with the aim of relating cold fronts to merger activity, understanding the dynamics of mergers and their effect on the cluster constituents. The Chandra X-ray imagery of Abell 1201 reveals two conspicuous surface brightness discontinuities that are shown to be cold fronts, and a remnant core structure. Temperature maps reveal a complex multiphase temperature structure with regions of hot gas interspersed with fingers of cold gas. Our optical analysis is based on a sample of 321 confirmed members, whose mean redshift is z = 0.1673 ± 0.0002 and velocity dispersion is 778 ± 36 km s−1. We search for dynamical substructure and find clear evidence for multiple localized velocity substructures coincident with overdensities in the galaxy surface density. Most notably, we find the structure coincident with the remnant X-ray core. Despite the clear evidence for dynamical activity, we find the peculiar velocity distribution does not deviate significantly from Gaussian. We apply two-body dynamical analyses in order to assess which of the substructures are bound, and thus dynamically important in terms of the cluster merger history. We propose that the cold fronts in Abell 1201 are a consequence of its merger with a smaller subunit, which has induced gas motions that gave rise to “sloshing” cold fronts. Abell 1201 illustrates the value of combining multiwavelength data and multiple substructure detection techniques when attempting to ascertain the dynamical state of a cluster.