OBSERVATION OF HIGH-ENERGY GAMMA-RAYS FROM THE QUASI-STELLAR OBJECT CTA-102

The quasar CTA 102 (QSO 2230+114) was observed 4 times in 1991-1992 by the EGRET high-energy gamma-ray telescope on the Compton Gamma-Ray Ob servatory satellite. In the 1992 January 23-February 6 observation, em ission was detected at the level (2.4 +/- 0.5) x 10(-7) photons cm-2 s -1 (E > 100 MeV). The other observations produced upper limits or dete ctions with lower significance which are consistent with the same flux . The photon spectrum can be represented by a power law with a number index of 2.6 +/- 0.2, the softest so far observed by EGRET. The emitte d gamma-ray luminosity, if isotropic, is 5 x 10(47) ergs s-1 (H0 = 75 km s-1 Mpc-1, q0 = 0.5), although there are good reasons to believe th at the gamma emission is strongly beamed.