Does black hole spin play a key role in the FSRQ/BL Lac dichotomy?

作     者：Debbijoy Bhattacharya Parameswaran Sreekumar Banibrata Mukhopadhyay Ishan Tomar 

作者机构：Manipal Centre for Natural SciencesManipal UniversityManipal 576104India Indian Institute of AstrophysicsBangalore 560034India Astronomy and Astrophysics ProgrammeDepartment of PhysicsIndian Institute of ScienceBangalore 560012India Space Astronomy GroupISRO Satellite CentreKarthik NagarBangalore 560037India 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2016年第16卷第4期

页      面：7-14页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：partially supported by projects SB/S2HEP-001/2013 funded by DST(DB) ISRO/RES/2/367/10-11 funded by ISRO,India 

主　　题：BL Lacertae objects: general    quasars: general    galaxies: jets    black hole physics   relativistic processes    gravitation 

摘      要：Blazars are characterized by large intensity and spectral variations across the electromagnetic spectrum It is believed that jets emerging from them are almost aligned with the line-of-sight. The major- ity of identified extragalactic sources in γ-ray catalogs of EGRET and Fermi are blazars. Observationally, blazars can be divided into two classes： fiat spectrum radio quasars （FSRQs） and BL Lacs. BL Lacs usually exhibit lower γ-ray luminosity and harder power law spectra at γ-ray energies than FSRQs. We attempt to explain the high energy properties of FSRQs and BL Lacs from Fermi γ-ray space telescope observations. It was argued previously that the difference in accretion rates is mainly responsible for the large mismatch in observed luminosity in ＂7-ray. However, when intrinsic luminosities are derived by correcting for beaming effects, this difference in 7-ray luminosity between the two classes is significantly reduced. In order to ex- plain this difference in intrinsic luminosities, we propose that spin plays an important role in the luminosity distribution dichotomy of BL Lacs and FSRQs. As the outflow power of a blazar increases with increasing spin of a central black hole, we suggest that the spin plays a crucial role in making BL Lac sources low luminous and slow rotators compared to FSRQ sources.