The universal shape of the X-ray variability power spectrum of AGN up to z ∼ 3
The universal shape of the X-ray variability power spectrum of AGN up to z ∼ 3
复制标题
AGN 高达 z ≤ 3 的 X 射线变异功率谱的通用形状
DOI：
10.1051/0004-6361/202245291
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发表时间：
2023
影响因子：
6.5
通讯作者：
Gilli, R.
中科院分区：
文献类型：
--
作者：
Paolillo, M.;Papadakis, I. E.;Brandt, W. N.;Bauer, F. E.;Lanzuisi, G.;Allevato, V.;Shemmer, O.;Zheng, X. C.;De Cicco, D.;Gilli, R.
AimsWe研究了活动星系核（AGN）在大范围时间尺度（20 ks ≤T≤ 14 yr）、红移（0 ≤z ≤ 3）、光度（1040 erg s-1≤LX≤ 1046 erg s-1）和黑洞（BH）质量（106≤M ≤ 109）上的系综X射线变率特性。它没有显示出任何证据表明形状或振幅随红移或光度的系统演化，即使在给定的红移或光度下，单个活动星系核之间可能存在差异。我们发现了新的证据，PSD的弯曲频率取决于BH的质量，并可能对吸积率。最后，我们讨论了当前和未来的AGN人口和宇宙学研究的影响。
AimsWe study the ensemble X-ray variability properties of active galactic nuclei (AGN) over large ranges of timescale (20 ks ≤T≤ 14 yr), redshift (0 ≤z≲ 3), luminosity (1040erg s−1≤LX≤ 1046erg s−1), and black hole (BH) mass (106≤M⊙≤ 109).MethodsWe propose the use of the variance-frequency diagram as a viable alternative to the study of the power spectral density (PSD), which is not yet accessible for distant, faint, and/or sparsely sampled AGN.ResultsWe show that the data collected from archival observations and previous literature studies are fully consistent with a universal PSD form, which does not show any evidence for systematic evolution of shape or amplitude with redshift or luminosity, even if there may be differences between individual AGN at a given redshift or luminosity. We find new evidence that the PSD bend frequency depends on BH mass and possibly on accretion rate. We finally discuss the implications for current and future AGN population and cosmological studies.