Abstract
High-energy gamma-ray emission has been detected from the quasar PKS 0208-512 in the energy range above 30 MeV by the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory. This region of sky was observed in five different viewing periods, and evidence of time variability in the gamma-ray emission by more than a factor of 3 was found. At the maximum intensity between 1991 September 19 and October 3, the flux density above 100 MeV was (9.1 +/- 0.4) x 10 exp -7 gamma/sq cm per sec. The photon spectrum during this period may be expressed as a power law with an exponent of - 1.69 +/- 0.05 between 30 MeV and 4 GeV. This is the hardest quasar spectrum observed by EGRET up to the present time.
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