The log N-log S graph for the COS-B galactic-ray sources.

Abstract

As a tool to the study of the collective properties of the 26 low-galactic-latitude γ-ray sources in the second CO S-B catalog their integral number-intensity relation, log N( > S, is investigated. The difficulty of accounting for the large flux errors is overcome by a simple Monte Carlo method. Especially when experimental selection effects are removed, significant differences are evident in the graph referring to the "center" (300° < l^II < 60°) and "anticenter" regions of the Galaxy. Such differences may be explained in terms of two populations of γ-ray sources, one being characterized by a marked density gradient toward the inner Galaxy.