PROBING OF THE INTERACTIONS BETWEEN THE HOT PLASMAS AND GALAXIES IN CLUSTERS FROM z = 0.1 TO 0.9
PROBING OF THE INTERACTIONS BETWEEN THE HOT PLASMAS AND GALAXIES IN CLUSTERS FROM z = 0.1 TO 0.9
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DOI：
10.1088/0004-637x/767/2/157
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发表时间：
2013-03
期刊：
影响因子：
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通讯作者：
L. Gu;P. Gandhi;N. Inada;M. Kawaharada;T. Kodama;S. Konami;K. Nakazawa;K. Shimasaku;Haiguang X
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文献类型：
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作者：
L. Gu;P. Gandhi;N. Inada;M. Kawaharada;T. Kodama;S. Konami;K. Nakazawa;K. Shimasaku;Haiguang X
根据34个红移为0.1-0.9的弛豫富星系团的光学和X射线数据，研究了团星系和热等离子体两种主要重子含量的相对空间分布。使用UH 88望远镜拍摄的多波段光度数据，我们使用两种独立的方法确定了每个星系团中成员星系的综合（二维）径向光剖面，即，背景减除和颜色幅度滤波。在我们的样本中，每个集群的内介质（ICM）的质量分布，也集成在两个维度上，来自空间分辨光谱分析使用XMM-牛顿和钱德拉数据。然后，每个星系团的径向积分光分布除以其ICM质量分布，以获得“星系光与ICM质量比”的分布。当样本被分成三个红移间隔分别为z = 0.11-0.22、0.22-0.45和0.45-0.89的子样本时，发现在中心0.65 R500区域的比率分布从红移较高的子样本到红移较低的子样本变陡，这意味着星系在ICM球中变得更加集中。一个Kolmogorov-Smirnov测试表明，在集群结构的这种演变是显着的在10.94%的置信水平。一系列的系统的不确定性，在星系光测量，以及许多半径/红移依赖的偏差与ICM配置文件的星系，已被评估，但没有一个是显着的对观察到的演变。此外，星系光与总质量比的分布也呈现出向低红移方向逐渐集中的特征。我们解释了星系、ICM和暗物质成分在早期阶段（z > 0.5）遵循类似的空间分布，而星系相对于其他星系向中心下降。这样的星系坠落很可能是由ICM对星系施加的阻力引起的，因为它们穿过ICM并与之相互作用，而引力阻力可以增强最大质量星系的坠落。
Based on optical and X-ray data for a sample of 34 relaxed rich clusters of galaxies with redshifts of 0.1–0.9, we studied relative spatial distributions of the two major baryon contents, the cluster galaxies and the hot plasmas. Using multi-band photometric data taken with the UH88 telescope, we determined the integrated (two-dimensional) radial light profiles of member galaxies in each cluster using two independent approaches, i.e., the background subtraction and the color–magnitude filtering. The intracluster medium (ICM) mass profile of each cluster in our sample, also integrated in two dimensions, was derived from a spatially resolved spectral analysis using XMM-Newton and Chandra data. Then, the radially integrated light profile of each cluster was divided by its ICM mass profile, to obtain a profile of “galaxy light versus ICM mass ratio.” When the sample is divided into three subsamples with redshift intervals of z = 0.11–0.22, 0.22–0.45, and 0.45–0.89, the ratio profiles over the central 0.65 R500 regions were found to steepen from the higher- to lower-redshift subsamples, meaning that the galaxies become more concentrated in the ICM sphere toward lower redshifts. A Kolmogorov–Smirnov test indicates that this evolution in the cluster structure is significant on ⩾94% confidence level. A range of systematic uncertainties in the galaxy light measurements, as well as many radius-/redshift-dependent biases to the galaxy versus ICM profiles, have been assessed, but none of them are significant against the observed evolution. Besides, the galaxy light versus total mass ratio profiles also exhibit gradual concentration toward lower redshift. We interpret that the galaxies, the ICM, and the dark matter components followed a similar spatial distribution in the early phase (z > 0.5), while the galaxies have fallen toward the center relative to the others. Such galaxy infall is likely to be caused by the drag exerted from the ICM to the galaxies as they move through the ICM and interact with it, while gravitational drag can enhance the infall of the most massive galaxies.