CHARACTERISTICS OF GALACTIC GAMMA-RAY SOURCES IN THE 2ND EGRET CATALOG

The second catalog of high-energy gamma-ray sources (> 100 MeV) has be en derived from the EGRET all sky survey (Phase 1) and the pointed obs ervations obtained during Phase 2 of the Compton Observatory mission. This catalog uses not only more data but also an improved model of the diffuse galactic gamma-ray background which is essential for the anal ysis of point sources. 129 sources were detected. They include identif ied sources (a solar flare, five pulsars, the Large Magellanic Cloud a nd 51 active galactic nuclei, AGN) as well as sources for which no ide ntification with objects at other wavelengths is yet available. We pre sent a short summary of the 2EG catalog and derive properties of the l ow galactic latitude population of unidentified gamma-ray sources base d on assumptions on their distribution in the Galaxy. The typical lumi nosity of galactic unidentified sources above 100 MeV must be in the r ange 6 10(34) to 4 10(35) erg/s in order to be compatible with their o bserved spatial galactic distribution and the spectrum of their fluxes .