Spectral Studies of Blazars in the GeV-TeV Range

Blazars, the most extreme class of active galactic nuclei (AGN), are characterized by strong flux variability across all wavelengths and relativistic jets pointing in Earth’s line of sight. The high-energy spectral study of blazars at the GeV-TeV range provides insight into the particle acceleration and gamma-ray emission mechanisms in blazar jets. Detailed Fermi-LAT analyses of a sample of blazars detected by VERITAS, atmospheric Cherenkov telescopes located at the Fred Lawrence Whipple Observatory, were performed to investigate the long-term gamma-ray variability of TeV blazars. A Bayesian blocks analysis was used to identify steady-flux periods for parameterization of the gamma-ray spectral cutoff. The correlation between gamma-ray hardness and flux was examined. We report on the results of flux and spectral variability of these blazars.