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北美退伍军人节(Veterans Day),12 日无更新
arXiv 2010.04832astro-ph.GA
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$z\sim0.4$上X射线AGN活度的环境依赖性

The environmental dependence of X-ray AGN activity at $z\sim0.4$

E. Noordeh, R. E. A. Canning, A. King, S. W. Allen, A. Mantz, R. G. Morris, S. Ehlert, A. von der Linden, W. N. Brandt, B. Luo, Y. Q. Xue, P. Kelly

摘要:

本文分析了红移范围为$0.35<z<0.45$的七个大质量星系团中活动星系核(AGN)的X射线分布。我们利用高质量的钱德拉X射线成像来鲁棒地识别活动星系核并精确地确定星系团的质量和质心。后续的VIMOS光谱学使我们能够确定哪些活动星系核是星系团成员。对光度为$>6.8\times10^{42}~\mathrm{erg~s^{-1}}$ 0.5-8 keV的活动星系核子集的研究发现,在$r\leq2r_{500}$(近似维里半径)范围内,星系团活动星系核的空间密度与星系团质量成$\sim M^{-2.0^{+0.8}_{-0.9}}$的比例关系。这一结果排除了在2.5 $σ$水平上星系团X射线活动星系核空间密度的零质量依赖性。我们比较我们的集群X射线活动星系核样本的控制领域具有相同的选择,并发现集群活动星系核的分数是显着抑制相对于外地时,考虑最明亮的星系与$V<21.5$。对于较暗的星系,这种差异并不存在。通过比较星系团成员活动星系核与对照区的X射线硬度比,我们没有发现星系团成员活动星系核X射线遮蔽增强的证据。最后,我们看到初步的证据表明,扰动集群环境可能有助于增强活动星系核活动。

英文摘要:

We present an analysis of the X-ray Active Galactic Nucleus (AGN) population in a sample of seven massive galaxy clusters in the redshift range $0.35<z<0.45$. We utilize high-quality Chandra X-ray imaging to robustly identify AGN and precisely determine cluster masses and centroids. Follow-up VIMOS optical spectroscopy allows us to determine which AGN are cluster members. Studying the subset of AGN with 0.5-8 keV luminosities $>6.8\times10^{42}~\mathrm{erg~s^{-1}}$, within $r\leq2r_{500}$ (approximately the virial radius), we find that the cluster AGN space density scales with cluster mass as $\sim M^{-2.0^{+0.8}_{-0.9}}$. This result rules out zero mass dependence of the cluster X-ray AGN space density at the 2.5$σ$ level. We compare our cluster X-ray AGN sample to a control field with identical selection and find that the cluster AGN fraction is significantly suppressed relative to the field when considering the brightest galaxies with $V<21.5$. For fainter galaxies, this difference is not present. Comparing the X-ray hardness ratios of cluster member AGN to those in the control field, we find no evidence for enhanced X-ray obscuration of cluster member AGN. Lastly, we see tentative evidence that disturbed cluster environments may contribute to enhanced AGN activity.

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。

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