标题： 活动星系核中的覆盖因子：演化与选择 显示英文标题

标题： Covering factor in AGNs: evolution versus selection

摘要： 在所有针对活动星系核（AGN）的统一模型方案中，一个关键要素是存在以环状结构分布的核区尘埃。在此背景下，一个至关重要的模型参数是覆盖因子（CF），定义为尘埃环的红外光度 $L_{\rm IR}$ 与吸积盘总辐射光度 $L_{\rm agn}$ 的比值。 本研究旨在确定覆盖因子的演化是否真实存在，或者选择效应对其有显著影响。 基于来自五大主要巡天项目（SDSS、GALEX、UKIDSS、WISE、SPITZER）的交叉匹配多波段测光数据，我们得到了一个包含近2000个类星体的样本。 类星体的主要参数，如黑洞质量及爱丁顿比率，是根据光谱数据计算得出的。 数据被分为两个红移区间：低红移 $z$ （约 \( z \sim 1 \)）和高红移 $z$ （约 \( z \sim 2 \)）类星体。 我们发现 WISE W4 滤光片的精度存在问题。 在可行的情况下，建议使用 SPITZER MIPS 24 \($\mu$\mu m \) 数据。 对于质量最高的斯皮策数据，计算得到的中位数 CF 值在误差范围内是可比较的，即$\log$CF$_{\textrm{low}-z} = -0.19\pm 0.11$和$\log$ CF$_{\textrm{high}-z}= -0.18\pm 0.11$。 Efron 和 Petrosian 检验确认了两者在红移过程中都存在光度演化，即$L_{\rm IR}$和 $L_{\rm agn}$。 低质量的$z$和高质量的$z$样本显示出$L_{\rm agn}$和$L_{\rm IR}$之间相似的相关性。 在高 SMBH 质量或高光度的类星体子样本中，未观察到 CF 的明显演化。 $L_{\rm IR}$和$L_{\rm agn}$之间的关系略微偏离预期的 1:1 比例关系。 然而，在整个数据集中无法声称 CF 对光度有统计上显著的依赖性。 显示英文摘要

摘要： In every proposed unification scheme for Active Galactic Nuclei (AGN), an integral element is the presence of circumnuclear dust arranged in torus-like structures. A crucial model parameter in this context is the covering factor (CF), defined as the ratio between the infrared luminosity of the dusty torus $L_{\rm IR}$, and the accretion disk bolometric luminosity $L_{\rm agn}$. Our study aims to determine whether CF evolution is genuine or if selection effects significantly influence it. Based on cross-matched multiwavelength photometrical data from the five major surveys (SDSS, GALEX, UKIDSS, WISE, SPITZER), a sample of almost 2,000 quasars was derived. The main parameters of quasars, such as black hole masses and the Eddington ratios, were calculated based on the spectroscopic data. The data were divided into two redshift bins: Low-$z$ (redshift ~1) and High-$z$ (redshift ~2) quasars. We identified an issue with the accuracy of the WISE W4 filter. Whenever feasible, it is recommended to utilize SPITZER MIPS 24 $\mu$m data. The calculated median CF values for the highest quality SPITZER data are comparable within errors $\log$ CF$_{\textrm{low}-z} = -0.19\pm 0.11$ and $\log$ CF$_{\textrm{high}-z}= -0.18\pm 0.11$. The Efron & Petrosian test confirmed the presence of luminosity evolution with redshift for both $L_{\rm IR}$ and $L_{\rm agn}$. Both the Low-$z$ and High-$z$ samples exhibit a similar correlation between $L_{\rm agn}$ and $L_{\rm IR}$. No discernible evolution of the CF was observed in the subsample of quasars with high SMBH mass bin or high luminosities. The relationship between $L_{\rm IR}$ and $L_{\rm agn}$ deviates slightly from the expected 1:1 scaling. However, no statistically significant dependence of CF on luminosities could be claimed across the entire dataset.