Wolf-Rayet stars and black holes: mass distributions and evolutionary connection

The form and relationship between the mass distributions of Wolf-Rayet stars and black holes are analyzed using a direct method for estimating the distribution function from a sample of mass values with individual distributions obtained from current observations. It is shown that, taking into account the mass loss of WR stars by the end of this evolutionary stage, the mass distribution of black holes is close to that of the CO-cores of WR stars before gravitational collapse, $M_{\mathrm{B}\mathrm{H}}\simeq M_{\mathrm{C}\mathrm{O}}$.