Estimation of inverse Compton peak frequency for 4FGL Blazars  

作　　者：JiangHe Yang JunHui Fan Yi Liu ManXian Tuo ZhiYuan Pei WenXin Yang YuHai Yuan SiLe He ShengHui Wang XiaoHai Qu YueLian Zhang JianJun Nie XiuHui Chen 

机构地区：[1]College of Mathematics and Physics Science,Hunan University of Arts and Science,Changde 415000,China [2]Center for Astrophysics,Guangzhou University,Guangzhou 510006,China [3]Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province,Guangzhou 510006,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2023年第4期142-157,共16页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.U2031112,U2031201,and 11733001);the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2019B030302001);the Research Fund of Hunan Education Department(Grant No.20C1273);the Science Research Grants from the China Manned Space Project(Grant No.CMS-CSST-2021-A06);the support from Astrophysics Key Subjects of Guangdong Province and Guangzhou City;supported by the Guangzhou University(Grant No.YM2020001)。

摘　　要：This study uses a parabolic equation to fit the Inverse Compton (IC) spectral component of 3743 blazars (794 FSRQs,1432 BLLacs,and 1517 BCUs) from the 4FGL-DR3 catalog.Some mutual correlations are investigated,and a Bayesian classification is performed to the IC peak frequencies.Our analyses draw the following conclusions:(1) The Bayesian classification shows two components with a dividing boundary of log(v_(p)^(IC)/Hz)pIC=22.9.Therefore,the 3743 blazars are divided into low IC peak frequency(LCP) blazars and high IC peak frequency (HCP) blazars.(2) A strong linear correlation exists between IC peak frequency(logv_(p)^(IC)) and γ-ray photon spectral index (Γ).The IC peak frequency can be estimated by an empirical relation logv_(p)^(IC)=–4.5·Γ+32.8 for BL Lacs and logv_(p)^(IC)=4.0+31.4pICfor FSRQs,which is consistent with the result by Abdo et al.(3) The ICspectral curvature and IC peak frequency are not as closely related as the synchrotron curvature and the synchrotron peak frequency.(4) An anti-correlation exists between IC peak frequency and IC peak luminosity,implying that as the IC peak frequency in the γ-ray band decreases,the source becomes more luminous.The beaming effect is stronger for the source with a lower IC peak frequency.(5) Positive correlations exist between IC and synchrotron components for both peak frequencies and peak fluxes,but no clear correlation exists between IC curvature and synchrotron curvature.

关 键 词：active galactic nuclei Fermi blazars spectral energy distribution inverse Compton emission 

分 类 号：P15[天文地球—天文学]