Correlation between γ-ray and radio emissions in Fermi blazars

• Published in: Publications of the Astronomical Society of Japan 2014-12, Vol.66 (6)
• Main Authors: Wu, De-Xiang, Fan, Jun-Hui, Liu, Yi, Yang, Jiang-He, Hao, Jing-Meng, Pei, Zhi-Yuan, Lin, Chao
• Format: Article
• Language: English
• ISSN: 0004-6264; 2053-051X
• DOI: 10.1093/pasj/psu111

Blazars as a special subclass of Active Galactic Nuclei (AGNs) consist of two classes, namely Flat Spectrum Radio Quasars (FSRQs) and BL Lacertae objects (BL Lacs). We compiled information about core and extended radio emissions of 124 γ-ray (0.1–100 GeV) loud blazars (79 FSRQs and 45 BL Lacs). Correlation is found between γ-ray and 5 GHz radio luminosities when the dependence of these two parameters on redshift is taken into account. The correlation suggests that, as well as the radio emission, the γ-ray emission may be strongly beamed. We find no correlation between the γ-ray luminosity (Lγ) and the core-dominance parameter R = Lcore/Lext, where Lcore is the VLBI core emission at 5 GHz, Lext is the extended (lobe) radio emissions at 5 GHz, but there is a strong correlation between log(Lγ/Lext) and log(1 + R).