Properties of Milky Way globular clusters associated with X-ray sources

The integral X-ray luminosities of 89 Milky Way Globular Clusters within 2 core radii r_c have been estimated using the average X-ray fluxes of individual sources detected in the recent Chandra, XMM-Newton or Swift missions. The X-ray luminosity function is constructed and a limit luminosity L_X([0.5-7] keV) = 10^33.65 erg s^-1 is defined, which divides the sample into two groups: 18 high-luminosity clusters and 71 low-luminosity clusters. For both subsamples the Kolmogorov-Smirnov test was applied for the parameters ellipticity, eccentricity of the orbit and estimated number of intermediate mass black holes. The test results show that at a confidence level of 99.9%, the high X-ray luminosity clusters have fewer black holes with intermediate mass than the low X-ray luminosity clusters. In addition, the former have lower ellipticity and higher eccentricity compared to the latter, but at significantly lower confidence levels of 80%.