The number-intensity relation for galactic gamma-ray sources and the emission from the galactic disk

Abstract

The paper evaluates the contribution of unresolved gamma-ray sources to overall emission of the Galaxy starting from the data on the resolved ones listed in the 1st COS-B catalogue, covering up to 50 percent of the galactic plane. It is shown that the integral Log N (greater than S)-Log S graph of an homogeneous subject of 9 of the 13 COS-B sources gives an analytical proof of the galactic nature of gamma-ray sources and allows the setting of constraints on the luminosity function of the gamma-ray sources. It is also noted that the 'diffuse' gamma-ray emission of the galactic disk and its overall luminosity, when used as boundary conditions, makes it possible to put constraints on the galactocentric distribution of the gamma-ray sources. Finally, it is concluded that gamma-ray sources contribute at least 30 percent of the gamma-ray luminosity of the Galaxy, the limit obtained with a uniform distribution of sources.