The distribution of the galactic compact X-ray sources: a statistical analysis.

A statistical analysis of the distribution in galactic longitude of the compact galactic X-ray sources listed in the Uhuru catalog shows that the distribution is not significantly inconsistent with a uniform space distribution of the sources throughout the galactic disk, provided that, as usually assumed, the Uhuru sample is complete for Lx > 1036 ergs 5 . In this scenario, however, there is a significant excess of sources at small distances from the Sun. Upon examining the matter of completeness of the Uhuru sample, it is found that a source having Lx = 1036 ergs 1 could not be detected from a distance beyond the galactic center, and only sources having Lx > 1 0 ergs s ' should be detectable everywhere in the Galaxy. We thus conclude that a significant number of weaker sources should be found by a detector with a better angular resolution than the Uhuru, and that the concentration of sources at longitudes near the galactic center reflects a real concentration of the sources toward the center of the Galaxy. Subject headings: galaxies: structure - X-ray: sources