Modification of the gamma-ray spectra by internal absorption in OVV blazars: The example cases of 3C 273 and 3C 279

Understand

Recent observations with the low threshold Cherenkov telescopes proved that sub-TeV gamma-rays are able to arrive from active galaxies at relatively large distances in spite of expected severe absorption in the extragalactic background light (EBL).

• We calculate the gamma-ray spectra at TeV energies from two example OVV quasars, 3C 273 and 3C 279, assuming that gamma-rays are injected in the inner parts of the jets launched by the accretion disks.
• It is assumed that gamma-rays in the broad energy range (from MeV up to TeV) are produced in these blazars with the power law spectrum with the spectral index as observed from these objects by the EGRET telescope at GeV energies.
• We take into account the internal absorption of these gamma-rays by considering a few different models for the radiation field surrounding the jet.