Observations of the 100 MeV Gamma-Ray Sources at Energies of 100-1000 GeV

Of the sources of gamma rays at energies of 70 MeV discovered by the SAS-2 and COS-B groups, eight were observed with the 10 m reflector on Mt. Hopkins in southern Arizona. All of the observations were in the winter of 1976/7. Because of the positional uncertainty of many of the sources, the detector configuration used was a modified version of that used in the recent high energy Sky Survey. Drift-scans were made on the following sources: (136 deg, + 1 deg), (196 deg, + 4 deg), (120 deg, 0 deg), (98 deg, 0 deg), (187 deg, 0 deg), (175 deg, -5 deg), and (78 deg, 1 deg). The latter scans also included the position of Cyg X-3. At the sensitivity achieved in these observations, none of these sources gave a detectable high energy gamma ray flux.