Transrelativistic pair plasmas in AGN jets

Models of relativistic jets filled with ultrarelativistic pair plasma are very successful in explaining the broadband radiation of $\gamma$-ray blazars. Assuming that the initial injection and cooling of ultrarelativistic pair plasma in an AGN jet has occurred, producing the observed high-energy $\gamma$-ray radiation, we investigate the further evolution of the pair plasma as it continues to move out from the central engine. The effects of thermalization and reacceleration, the emission of pair bremsstrahlung and annihilation radiation and the bulk Compton process, and the possible application to MeV blazars are discussed. A model calculation to the special case of PKS~0208-512 is presented.