Fermi Gamma-ray Space Telescope

Blazar variability and evolution in the GeV regime

Shimpei Tsujimoto
Junko Kushida, Kyoshi Nishijima and Kazuhito Kodani

Abstract:

One of the most important probrem of the blazar astrophysics is to understand the physical origin of the blazar sequence. In this study, we focus on the GeV gamma-ray variability of blazers and from a evolution perspective we search the relation between the redshift and the variability amplitude of blazars for each blazar subclass. We analyzed the Fermi-LAT data of the TeV blazars and the bright AGNs (flux $geq$ $5 times 10^{-9}$ [cm$^{-2}$ s$^{-1}$]) selected from the 2LAC (the 2nd LAT AGN catalog) data base. As a result, we found a hint of the correlation between the redshift and the variability amplitude in the FSRQs. Furthermore the BL Lacs which have relatively lower peak frequency of the synchrotron radiation and relatively lower redshift, have a tendency to have a smaller variability amplitude.