KMS National Astronomical Observatories, CAS
On the Origin and Evolution of Curvature of the Spectral Energy Distribution of Fermi Bright Blazars | |
Anjum, Muhammad S.1,2; Chen, Liang1; Gu, Minfeng1 | |
2020-07-01 | |
Source Publication | ASTROPHYSICAL JOURNAL
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ISSN | 0004-637X |
Volume | 898Issue:1Pages:10 |
Abstract | The origin and evolution of spectral curvature in blazar spectral energy distribution (SED) is still unclear. Since the observed SED curvature is related to an intrinsic curvature in emitting electron energy distribution (EED), we study this question by employing a log-parabolic EED with a curvature parameter and peak energy to model the quasi-simultaneous broadband SEDs of selected blazars in the Fermi-LAT Bright AGN Sample using synchrotron and inverse Compton (IC) processes. We find that the log-parabolic IC model can successfully explain the emission in all blazars in our sample. On average, FSRQs have higher magnetic field, Doppler factor, and curvature than BL Lac objects. The BL Lac objects show an anticorrelation between the curvature parameter of the EED and its peak energy, which is a signature of stochastic acceleration. FSRQs do not manifest such correlation and rather show a mild positive relationship between these parameters. This suggests that the evolution of spectral curvature in the BL Lac objects is dominated by a strong stochastic acceleration component, whereas the curvature in FSRQs evolves in a cooling dominated regime due to an additional external Compton component. The strong cooling in FSRQs not only restricts the electron peak energy but also adds extra curvature to the high energy tail of emitting EED. Since the curvature decreases from FSRQs toward high peak BL Lac objects (HBLs), opposite to peak energy, the curvature parameter can be considered a third parameter of the blazar sequence in addition to peak frequency and luminosity. |
Keyword | Blazars BL Lacertae objects High energy astrophysics High-luminosity active galactic nuclei Quasars |
Funding Organization | National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China |
DOI | 10.3847/1538-4357/ab99a1 |
WOS Keyword | ACTIVE GALACTIC NUCLEI ; LOG-PARABOLIC SPECTRA ; GAMMA-RAY FLARE ; PHYSICAL-PROPERTIES ; PARTICLE-ACCELERATION ; ELECTRON ACCELERATION ; RELATIVISTIC JETS ; RADIO QUASARS ; EMISSION ; VARIABILITY |
Language | 英语 |
Funding Project | National Natural Science Foundation of China[U1831138] ; National Natural Science Foundation of China[11873073] |
Funding Organization | National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; National Natural Science Foundation of China |
WOS Research Area | Astronomy & Astrophysics |
WOS Subject | Astronomy & Astrophysics |
WOS ID | WOS:000555721600001 |
Publisher | IOP PUBLISHING LTD |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://ir.bao.ac.cn/handle/114a11/82458 |
Collection | 中国科学院国家天文台 |
Corresponding Author | Anjum, Muhammad S. |
Affiliation | 1.Chinese Acad Sci, Shanghai Astron Observ, Key Lab Res Galaxies & Cosmol, 80 Nandan Rd, Shanghai 200030, Peoples R China 2.Univ Chinese Acad Sci, 19A Yuquan Rd, Beijing 100049, Peoples R China |
Recommended Citation GB/T 7714 | Anjum, Muhammad S.,Chen, Liang,Gu, Minfeng. On the Origin and Evolution of Curvature of the Spectral Energy Distribution of Fermi Bright Blazars[J]. ASTROPHYSICAL JOURNAL,2020,898(1):10. |
APA | Anjum, Muhammad S.,Chen, Liang,&Gu, Minfeng.(2020).On the Origin and Evolution of Curvature of the Spectral Energy Distribution of Fermi Bright Blazars.ASTROPHYSICAL JOURNAL,898(1),10. |
MLA | Anjum, Muhammad S.,et al."On the Origin and Evolution of Curvature of the Spectral Energy Distribution of Fermi Bright Blazars".ASTROPHYSICAL JOURNAL 898.1(2020):10. |
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