Modeling GeV spectral breaks in the Fermi-LAT observations of Bright Blazars

Full text: Active galactic nuclei (AGN) are among the most numerous sources in the high energy gamma-ray sky. Their non-thermal continuum emission is believed to originate in their relativistic collimated outflows (jets) which are directed perpendicular to their accretion disk, and are powered by a supermassive black hole. During the first years of operation the GeV sensitive LAT instrument onboard the Fermi Gamma-ray Space Telescope detected hundreds of blazars, a sub-type of AGN. Surprisingly, the spectra of very luminous blazars show prominent breaks at a few ∼GeV whose origin is not yet established. We investigate which parameter settings are required to produce such breaks in time-dependent emission models where the dominant gamma-ray radiation is produced by relativistic continuously injected electrons which inverse Compton scatter photons from the accretion disk and the broad-line region clouds in the vicinity of the jet. (author)