arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1202.3787astro-ph.CO
收藏

XMM星系团巡天:通过AGN反馈最亮星系团和星系团内介质之间的相互作用

The XMM Cluster Survey: The interplay between the brightest cluster galaxy and the intra-cluster medium via AGN feedback

John P. Stott, Ryan C. Hickox, Alastair C. Edge, Chris A. Collins, Matt Hilton, Craig D. Harrison, A. Kathy Romer, Philip J. Rooney, Scott T. Kay, Christopher J… 展开作者

John P. Stott, Ryan C. Hickox, Alastair C. Edge, Chris A. Collins, Matt Hilton, Craig D. Harrison, A. Kathy Romer, Philip J. Rooney, Scott T. Kay, Christopher J. Miller, Martin Sahlen, Ed J. Lloyd-Davies, Nicola Mehrtens, Ben Hoyle, Andrew R. Liddle, Pedro T. P. Viana, Ian G. McCarthy, Joop Schaye, C. M. Booth

摘要:

使用从XMM-星团巡天第一次数据发布中抽取的123个X射线星团和星团组的样本,我们研究了最亮的星团星系(BCG),它的黑洞和星团内/星团介质(ICM)之间的相互作用。看来,集团和集群与BCG可能主机显着AGN反馈,气体冷却占主导地位,在那些与Tx > 2 keV,而AGN反馈占主导地位以下。这可以通过我们在晕质量范围10^13 < M500 < 10^15Msol的BCG质量和星团质量之间的标度关系中发现的亚单位指数以及射电光度和星团质量之间缺乏相关性来理解,这样BCG AGN在组中可以对ICM产生相对更大的能量影响。对于具有最大质量的BCGs的系统,或者具有与ICM发射的峰值共同定位的BCGs的那些系统,Lx-Tx关系比具有最小质量和最大偏移的那些系统的Lx-Tx关系更陡峭,这反而遵循自相似性。这是证据表明,中央气体冷却和强大的,燃料充足的活动星系核的组合导致ICM从纯引力加热的出发,与陡峭的关系交叉自相似性在Tx = 2千电子伏。重要的是,不管它们的黑洞质量如何,如果它们在一个大质量的星系团中(Tx > 2 keV),并且再次与致密的冷却气体的有效燃料供应共存,那么BCGs更有可能拥有无线电噪音的活动星系核。这表明,最大质量的黑洞似乎比它们的宿主星系更了解它们的宿主星系团。结果导致我们提出了一个物理动机,经验的定义“集群”和“组”,划定在2千电子伏。

英文摘要:

Using a sample of 123 X-ray clusters and groups drawn from the XMM-Cluster Survey first data release, we investigate the interplay between the brightest cluster galaxy (BCG), its black hole, and the intra-cluster/group medium (ICM). It appears that for groups and clusters with a BCG likely to host significant AGN feedback, gas cooling dominates in those with Tx > 2 keV while AGN feedback dominates below. This may be understood through the sub-unity exponent found in the scaling relation we derive between the BCG mass and cluster mass over the halo mass range 10^13 < M500 < 10^15Msol and the lack of correlation between radio luminosity and cluster mass, such that BCG AGN in groups can have relatively more energetic influence on the ICM. The Lx - Tx relation for systems with the most massive BCGs, or those with BCGs co-located with the peak of the ICM emission, is steeper than that for those with the least massive and most offset, which instead follows self-similarity. This is evidence that a combination of central gas cooling and powerful, well fuelled AGN causes the departure of the ICM from pure gravitational heating, with the steepened relation crossing self-similarity at Tx = 2 keV. Importantly, regardless of their black hole mass, BCGs are more likely to host radio-loud AGN if they are in a massive cluster (Tx > 2 keV) and again co-located with an effective fuel supply of dense, cooling gas. This demonstrates that the most massive black holes appear to know more about their host cluster than they do about their host galaxy. The results lead us to propose a physically motivated, empirical definition of 'cluster' and 'group', delineated at 2 keV.

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。

↑