Formation of Black-Hole X-Ray Binaries with Low-Mass Donors
Abstract
Description
The characteristics of black-hole X-ray binaries can be used to obtain information about their evolutionary history and the process of black-hole formation. In this paper I focus on systems with donor masses lower than the inferred black-hole masses. Current models for the evolution of hydrogen-rich, massive stars and of helium stars losing mass in a wind cannot explain the current sample of black-hole mass measurements. Assuming that the radial evolution of mass-losing massive stars is at least qualitatively accurate, I show that the properties of the BH companions lead to constraints on the masses of black-hole progenitors (at most twice the black-hole mass) and on the strength of winds in helium stars (fractional amount of mass lost smaller than about 50%). Constraints on common-envelope evolution are also derived.
6 pages, 2 figures. Invited talk at ESO Workshop Black Holes in Binaries and Galactic Nuclei in Honour of Prof. R. Giacconi, eds. L. Kaper, E.P.J. van den Heuvel, and P.A. Woudt
6 pages, 2 figures. Invited talk at ESO Workshop Black Holes in Binaries and Galactic Nuclei in Honour of Prof. R. Giacconi, eds. L. Kaper, E.P.J. van den Heuvel, and P.A. Woudt