What is a cool-core cluster? a detailed analysis of the cores of the X-ray flux-limited HIFLUGCS cluster sample
What is a cool-core cluster? a detailed analysis of the cores of the X-ray flux-limited HIFLUGCS cluster sample
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DOI：
10.1051/0004-6361/200912377
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发表时间：
2009-11
影响因子：
6.5
通讯作者：
D. Hudson;R. Mittal;T. Reiprich;P. Nulsen;H. Andernach;C. Sarazin
中科院分区：
文献类型：
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作者：
D. Hudson;R. Mittal;T. Reiprich;P. Nulsen;H. Andernach;C. Sarazin
我们使用64个星系团（最高X射线通量星系团样本）的最大完整样本，并从钱德拉获得高质量的X射线数据，并对它们应用16个冷核诊断，其中一些是新的。为了确定表征冷核团簇的最佳参数并量化其与其他参数的关系，我们主要使用中心气体密度和温度的非常高的空间分辨率分布，以及从它们导出的量。我们还关联的最亮的星系团（BCGs）的光学特性与X射线特性。为了分离冷核和非冷核团簇，我们发现，中心冷却时间，t冷，是最好的参数低红移团簇与高质量的数据，和尖度是最好的参数高红移团簇。在我们的样本中，72%的星团在它们的BCG和X射线峰之间有一个冷核（t冷却50 h-1 71 kpc）。相比之下，56个星团中只有两个在BCG和X射线峰之间有很小的间隔（<50 h-1 71 kpc）显示出大规模的射电发射。基于这一结果，我们认为，一个大的预计分离之间的BCG和X射线峰值是一个很好的指标，一个重大的合并。讨论了弱冷核团簇作为中间类天体的性质。最后，我们描述了样本中所有64个聚类的个体属性。
We use the largest complete sample of 64 galaxy clusters (HIghest X-ray FLUx Galaxy Cluster Sample) with available high-quality X-ray data from Chandra, and apply 16 cool-core diagnostics to them, some of them new. In order to identify the best parameter for characterizing cool-core clusters and quantify its relation to other parameters, we mainly use very high spatial resolution profiles of central gas density and temperature, and quantities derived from them. We also correlate optical properties of brightest cluster galaxies (BCGs) with X-ray properties. To segregate cool core and non-cool-core clusters, we find that central cooling time, t cool , is the best parameter for low redshift clusters with high quality data, and that cuspiness is the best parameter for high redshift clusters. 72% of clusters in our sample have a cool core (t cool 50 h ―1 71 kpc) projected separation between their BCG and X-ray peak. In contrast, only two of the 56 clusters with a small separation between the BCG and X-ray peak (<50 h ―1 71 kpc) show large-scale radio emission. Based on this result, we argue that a large projected separation between the BCG and the X-ray peak is a good indicator of a major merger. The properties of weak cool-core clusters as an intermediate class of objects are discussed. Finally we describe individual properties of all 64 clusters in the sample.