Nonthermal gamma‐ray emission from blazars

The leading models proposed to explain the luminous hard γ‐ray emission from blazars observed by EGRET and COMPTEL are reviewed in light of the current observational information. The most recent multiwaveband data indicate that high γ‐ray states are associated with strong synchrotron flares at lower frequencies. Models involving inverse Compton scattering in a relativistic jet appear to hold the most promise of explaining the γ‐ray emission if one considers the general problem of explaining blazar emission across all wavebands. However, the source of the seed photons is controversial, with the synchrotron photons, ultraviolet photons from the putative accretion disk, and photons from diffuse scattering or emission‐line regions all competing with each other. Future intensive multiwaveband monitoring of bright γ‐ray blazars should lead us to the correct emission model, and may also uncover important clues regarding the nature of the particle acceleration and jet formation in quasars and similar objects.