Multi-Band Spectral Properties of Fermi Blazars

Journal of astrophysics and astronomy

Benzhong Dai1¹  Dahai Yan¹ 

[1] Department of Physics, Yunnan University, Kunming 650091, China.$$

关键词: Galaxies: active;    BL Lacertae objects;    general;    gamma rays;    observations.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

The multi-band data covering optical, X-ray and 𝛾-ray energy regions of 130 Fermi blazars in the First LAT AGN Catalog (1LAC) were collected to investigate the broadband spectral properties. The composite spectral indices show that HBLs have convex optical-to-X-ray continua and concave X-ray-to-𝛾-ray continua, 𝛼𝛾 𝑋𝛾 > 0 and 𝛼𝑋𝑂𝑋 < 0, while FSRQs and LBLs have 𝛼𝛾 𝑋𝛾 < 0. The 𝛼𝑋𝑂𝑋 distribution of FSRQs and LBLs extends from negative to positive values. We suggest 𝛼𝛾 𝑋𝛾 > 0 and 𝛼𝑋𝑂𝑋 < 0 could be considered as a criterion for HBLs. Moreover, HBLs have narrow distribution of peak interval of log $v^{ext{ic}}_{ext{p}}=log v^{ext{syn}}_{ext{p}}$, and FSRQs have significant anti-correlation between log $v^{ext{ic}}_{ext{p}}-log v^{ext{syn}}_{ext{p}}$ and $log v^{ext{syn}}_{ext{p}}$. This indicates that SSC model is responsible for high energy emission of HBLs, while EC for FSRQs. Our results also indicate that FSRQs with larger break energy of electrons have smaller bulk Lorentz factor of dissipation region.

【 授权许可】

Unknown