Study On γ - Ray Radiation Characteristics Of Fermi Yao Variant

Blazar is a subclass of active galactic nuclei(AGN) with special physical properties, and blazars show some extrme observations, such as relativistic jet,apparent superluminal motion. The radiation of blazars are continuous from the radio band to the high-energy gamma-band. It is generally considered that the radio to soft X-ray band radiation is caused by synchrotron radiation, but the origin of gamma ray radiation have not been consequenced. So it is very important to study the origin of gamma ray.In this paper, we chose two differently special Fermi-selected blazars samples.Using γ-ray band(1-100Gev) data detected by Fermi Large Area Telescope(LAT)and X-ray band data for 78 blazars, we find a medium correlation between X- ray flux and γ-ray flux in all states. A medium correlation is also found between X- ray(1 keV)mean spectral index αx and γ-ray mean spectral index αγfor BL Lacertae objects(BL Lacs), while there is no correlation for Flat Spectrum Radio Quasars(FSRQs). From these results, we suggest that the most likely radiation mechanism for the high energy gamma-rays would be synchrotron self-Compton(SSC), and that the gamma-ray emission mechanism may be somewhat different for BL Lacs and FSRQs.We collect 175 blazars in the second sample, which has 99 Fermi sources(29 BL Lacs and 70 FSRQs), and make the histogram about core luminosity, brightness temperature, core dominance parameters, apperent jet speed and Doppler factor for Fermi and non-Fermi blazars. We find that rightness temperature, core dominance parameters, apperent jet speed and Doppler factor for Fermi are higher than the average of non-Fermi blazars; FSRQs also have significantly higher jet parameters than the BL Lacs. Above results support that the Fermi blazars have stronger doppler boosting; γ-ray radiation,like radio radiation, is doppler boosting, and γ-ray radiation is from th jet; and the subclass FSRQs and BL Lacs may have different jet models.