Distribution of the calculated X-ray luminosities of the simulated XRBs in the default population with respect to the orbital separation. The population is further split by the type of XRB (RLO or wind), type of accretor (BH or NS), and type of donor (H-rich or He-rich). Be XRBs are shown with gray circles. Large and small symbols denote massive (with ≳8.0 M_⊙) and less massive (with < 8.0 M_⊙) XRBs, respectively.