The spatial distribution of pulsars in the Galaxy and the nature of the gamma sources

Given the fact that pulsars connected with gamma sources are concentrated in the spiral arms of the Galaxy, the distances of objects in the COS-B catalog can be estimated. The mean distance to 18 sources from this catalog is 2.9-3.3 kpc; the mean distance to the Galactic plane, corresponding to the inner and outer solar Galactic orbit, is 50-70 and 150 pc, respectively. The average gamma-luminosity for energies greater than or about 100 MeV is (5-9) x 10 to the 34th erg/s. The present data indicate that the majority of the objects in the 2 COS-B catalog are pulsars which are not observed at radio frequency.