High redshift X-ray galaxy clusters. II. The L X T relationship revisited
High redshift X-ray galaxy clusters. II. The L X T relationship revisited
复制标题
高红移X射线星系团。
DOI：
10.1051/0004-6361:20077467
复制
发表时间：
2007
影响因子：
6.5
通讯作者：
U. Bologna
中科院分区：
文献类型：
--
作者：
M. Branchesi;I. Gioia;C. Fanti;R. F. I. D. R. Inaf;Bologna;Italy.;U. Bologna
目标。本文重新考察了高z星系团的X射线光度与温度之间的观测关系，并将其与局域LX-T和理论模型进行了比较。方法.为此，我们使用了从Chandra档案中提取的17个集群的样本，并补充了来自文献的其他集群，无论是Chandra还是XMM-牛顿，以形成39个高红移（0.25 < z < 1.3）对象的最终样本。采用不同的统计方法来分析LX-T关系。结果高红移星系团的LX-T关系的斜率比自相似模型预测的更陡，而且比局部LX-T斜率更陡，尽管在误差范围内仍然是相容的。遥远星系团LX-T关系显示出相对于本地宇宙的显著演化：在任何给定的温度下，高z星系团比本地星系团更明亮，亮度是本地星系团的1/2a。LX-T关系随红移的演化既不能用单一的幂律来描述，也不能用自相似模型所预言的演化来描述。结论.我们发现了一个强演化，类似于或强于自相似模型，从z = 0到oz ≤ 0。3f在更高的红移下，如果有的话，会有一个更弱的演化。较弱的演化与结构形成的非引力模型是相容的。我们认为，应该用现有的X射线望远镜观测到附近星团（z < 0.25）的统计学显著样本，以完全排除由于不同世代探测器造成的观测影响，并理解这一新结果。
Aims. In this paper we re-visit the observational relation between X-ray luminosity and temperature for high-z galaxy clusters and compare it with the local LX–T and with theoretical models. Methods. To these ends we use a sample of 17 clusters extracted from the Chandra archive supplemented with additional clusters from the literature, either observed by Chandra or XMM–Newton, to form a final sample of 39 high redshift (0.25 < z < 1.3) objects. Different statistical approaches are adopted to analyze the LX–T relation. Results. The slope of the LX–T relation of high redshift clusters is steeper than expected from the self-similar model predictions and steeper, even though still compatible within the errors, than the local LX–T slope. The distant cluster LX–T relation shows a significant evolution with respect to the local Universe: high-z clusters are more luminous than the local ones by a factor ≈ 2a t any given temperature. The evolution with redshift of the LX–T relation cannot be described by a single power law nor by the evolution predicted by the self-similar model. Conclusions. We find a strong evolution, similar or stronger than the self-similar model, from z = 0t oz ≤ 0. 3f ollowed by a much weaker, if any, evolution at higher redshifts. The weaker evolution is compatible with non-gravitational models of structure formation. According to us a statistically significant sample of nearby clusters (z < 0.25) should be observed with the current available X-ray telescopes to completely exclude observational effects due to different generation detectors and to understand this novel result.