SIMBAD references

We compute and present the distribution in mass of single and binary neutron stars, strange stars, and black holes. The calculations were performed using a stellar population synthesis code. We follow the evolution of massive single stars as well as binaries with high-mass primaries. The final product of the latter evolution can be either a binary composed of a white dwarf and a compact object (a neutron star, black hole, or strange star), two compact objects in a binary, or two single stars if the system was disrupted. We find in binaries a population of black holes that are more massive than single black holes that are a product of either binary or single evolution. We also find that if quark stars exist at all, their population can be as large as the population of black holes.