Systematically smaller single-epoch quasar black hole masses using a radius–luminosity relationship corrected for spectral bias
Systematically smaller single-epoch quasar black hole masses using a radius–luminosity relationship corrected for spectral bias
复制标题
使用校正光谱偏差的半径与光度关系系统地减小单历元类星体黑洞质量
DOI：
10.1093/mnras/stac1748
复制
发表时间：
2022
影响因子：
4.8
通讯作者：
on M Matthews
中科院分区：
文献类型：
--
作者：
Jaya Maithil;Michael S Brotherton;Ohad Shemmer;Pu Du;Jian-Min Wang;Adam D Myers;Jacob N McLane;Cooper Dix;Br;on M Matthews
摘要。以更高的准确度和精度确定黑洞质量和吸积率对于理解类星体作为一个群体至关重要。这些基本的物理性质是活动星系核模型的基础。测量黑洞质量的主要技术采用低红移类星体的混响映射，然后通过宽线区域的半径-亮度关系进行扩展，以基于单历元光谱估计质量。一个更新的半径-光度关系包括光学Fe ii与H β的通量比（$equiv mathcal {R}_{rm Fe}$），以校正更高吸积系统具有比以前实现的更小的线发射区域的偏差。在这项工作中，我们证明和量化的效果，使用这种铁校正的半径-光度关系的质量估计采用档案数据集拥有休息帧光谱在很宽的红移范围。我们发现，未能使用铁校正的半径预测结果高估单时代的黑洞质量的最高度吸积类星体。它们的吸积率测量（LBol/LEdd和$dot{mathscr{M}}$）同样被低估。最强的铁发射类星体分为两类：一类是具有静止坐标系光谱的高z类星体，由于它们具有极高的光度，需要高的吸积率;另一类是它们的低z类星体，由于它们的黑洞质量较低，必须具有高的吸积率才能满足巡天通量的限制。这些类平均有大约2倍的质量向下修正。这些结果加强了本征矢量1参数$mathcal {R}_{rmFe}$与吸积过程的联系。
ABSTRACT. Determining black hole masses and accretion rates with better accuracy and precision is crucial for understanding quasars as a population. These are fundamental physical properties that underpin models of active galactic nuclei. A primary technique to measure the black hole mass employs the reverberation mapping of low-redshift quasars, which is then extended via the radius–luminosity relationship for the broad-line region to estimate masses based on single-epoch spectra. An updated radius–luminosity relationship incorporates the flux ratio of optical Fe ii to H β ($equiv mathcal {R}_{rm Fe}$) to correct for a bias in which more highly accreting systems have smaller line-emitting regions than previously realized. In this work, we demonstrate and quantify the effect of using this Fe-corrected radius-luminosity relationship on mass estimation by employing archival data sets possessing rest-frame optical spectra over a wide range of redshifts. We find that failure to use an Fe-corrected radius predictor results in overestimated single-epoch black hole masses for the most highly accreting quasars. Their accretion rate measures (LBol/LEdd and $dot{mathscr{M}}$ ) are similarly underestimated. The strongest Fe-emitting quasars belong to two classes: high-z quasars with rest-frame optical spectra, which, given their extremely high luminosities, require high accretion rates, and their low-z analogues, which, given their low black holes masses, must have high accretion rates to meet survey flux limits. These classes have mass corrections downward of about a factor of two, on average. These results strengthen the association of the dominant Eigenvector 1 parameter $mathcal {R}_{rm Fe}$ with the accretion process.