arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0806.0382astro-ph
收藏

星系团核心强H-α和射电辐射的熵阈值

An Entropy Threshold for Strong H-alpha and Radio Emission in the Cores of Galaxy Clusters

Kenneth W. Cavagnolo, Megan Donahue, G. Mark Voit, Ming Sun

摘要:

我们的钱德拉X射线天文台对222个星系团样本中的团内熵的档案研究表明,当星系团的核心气体熵< 30 keV cm ^2时,来自最亮星系团的H-α和射电发射要明显得多。低于这个阈值的H-α发射的普遍性表明,它标志着在核心中可以容纳多相气体和恒星形成的星团与不能容纳多相气体和恒星形成的星团之间的二分法。强的中心射电辐射也出现在这个边界以下的事实表明,当团内介质开始凝聚时,活动星系核反馈就会开启,加强了活动星系核反馈作为限制宇宙中最明亮星系中恒星形成的机制的情况。

英文摘要:

Our Chandra X-ray Observatory archival study of intracluster entropy in a sample of 222 galaxy clusters shows that H-alpha and radio emission from the brightest cluster galaxy are much more pronounced when the cluster's core gas entropy is < 30 keV cm^2. The prevalence of H-alpha emission below this threshold indicates that it marks a dichotomy between clusters that can harbor multiphase gas and star formation in their cores and those that cannot. The fact that strong central radio emission also appears below this boundary suggests that AGN feedback turns on when the intracluster medium starts to condense, strengthening the case for AGN feedback as the mechanism that limits star formation in the Universe's most luminous galaxies.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑