Search for gamma-radiation from extragalactic objects using a likelihood method.
Bignami, G. F.; Hermsen, W.; Masnou, J. L.; Pollock, A. M. T.; Kanbach, G.; Lichti, G. G.; Swanenburg, B. N.; Wills, R. D.
France, Italy, Netherlands
Abstract
A search through COS-B data for gamma-radiation from a number of extragalactic objects reveals no strong evidence for any positive identification except, as already reported, for the region around the quasar 3C273. Upper limits to the photon fluxes from active extragalactic objects are evaluated using a likelihood method. They reinforce the conclusion reached by Bignami et al. (1979) from the SAS-2 data that the flux upper limits lie substantially below the extrapolation of spectra measured at X-ray energies. The proposed identifications of 2CG135 plus 01 are also discussed.