Variations of broad emission lines from periodicity QSOs under the interpretation of supermassive binary black holes with misaligned circumbinary broad line regions  

作　　者：Xiang Ji Jun-Qiang Ge You-Jun Lu Chang-Shuo Yan 

机构地区：[1]CAS Key Laboratory for Computational Astrophysics,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [2]School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Research in Astronomy and Astrophysics》2021年第9期63-74,共12页天文和天体物理学研究（英文版）

基　　金：supported by the National Key R&D Program of China(Grant Nos.2020YFC2201400,2020SKA0120102,and 2016YFA0400704);the National Natural Science Foundation of China(Grant Nos.11690024,11873056,and 11991052);the Strategic Priority Program of the Chinese Academy of Sciences(Grant No.XDB 23040100);the Beijing Municipal Natural Science Foundation(Grant No.1204038)。

摘　　要：Quasars with periodic light curves are considered as candidates of supermassive binary black hole(BBH)systems.One way for further confirmations may be searching for other characteristic signatures,such as those in their broad emission lines(BELs),if any,which require a thorough understanding on the response of BELs to the BBH systems.In Ji et al.(2021),we have investigated the response of circumbinary broad line region(BLR)to the central active secondary black hole under the relativistic Doppler boosting(BBH-DB)and intrinsic variation(BBH-IntDB)dominant mechanisms for continuum variation by assuming the middle plane of the BLR aligned with the BBH orbital plane.In this paper,we explore how the BEL profiles vary when the BLR is misaligned from the BBH orbital plane with different offset angles under both the BBH-DB and BBH-IntDB scenarios.Given a fixed inclination angle of the BBH orbital plane viewed in edge-on and similar continuum light curves produced by the two scenarios,increasing offset angles make the initial opening angle of the circumbinary BLR enlarged due to orbital precession caused by the BBH system,especially for clouds in the inner region,which result in Lorentzlike BEL profiles for the BBH-DB model but still Gaussion-like profiles for the BBH-IntDB model at the vertical BLR case.The amplitude of profile variations decreases with increasing offset angles for the BBHDB scenario,while keeps nearly constant for the BBH-IntDB scenario,since the Doppler boosting effect is motion direction preferred but the intrinsic variation is radiated isotropically.If the circumbinary BLR is composed of a coplanar and a vertical components with their number of clouds following the mass ratio of the BBHs,then the bi-BLR features are more significant for the BBH-IntDB model that requires larger mass ratio to generate similar continuum variation than the BBH-DB model.

关 键 词：black hole physics QUASARS supermassive black holes emission lines profiles 

分 类 号：P145.8[天文地球—天体物理]