论文标题
X射线AGN活动在$ z \ sim0.4 $上的环境依赖性
The environmental dependence of X-ray AGN activity at $z\sim0.4$
论文作者
论文摘要
我们介绍了X射线活性银河核（AGN）种群的分析，其中有7个大型星系簇的样品在红移范围内$ 0.35 <z <z <0.45 $。我们利用高质量的Chandra X射线成像来稳健地识别AGN并精确确定簇质量和质心。后续VIMOS光谱范围使我们能够确定哪些AGN是群集成员。在$> 6.8 \ times10^{42}〜\ mathrm {erg〜s^{ - 1}} $中研究AGN的子集，$> 6.8 \ times10^{42}〜\ Mathrm {erg〜s^{ - 1}} $，in $ r \ leq2r_ {500} $（大约是病毒式radius），我们发现与cluster agn scales $ sculs sculs use sim sim sim m^{ - 2.0^{+0.8} _ { - 0.9}} $。该结果排除了在2.5 $σ$级别下群集X射线AGN空间密度的零质量依赖性。我们将群集X射线AGN样品与具有相同选择的对照场进行比较，并发现当考虑$ V <21.5 $的最明亮的星系时，相对于该场的群集AGN分数显着抑制。对于无效的星系，不存在这种差异。将群集成员AGN的X射线硬度比与对照场中的X射线硬度比进行比较，我们没有发现簇成员AGN的X射线遮挡的证据。最后，我们看到暂定的证据表明干扰的集群环境可能有助于增强AGN活性。
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.
