Galactic population of black holes in detached binaries with low-mass stripped helium stars: the case of LB-1 (LS~V+22~25)

We model the Galactic population of detached binaries that harbour black holes with 0.5-1.7 M-circle dot companions - remnants of case B mass exchange that rapidly cross Hertzsprung gap after the termination of the Roche lobe overflow or as He-shell burning stars. Several such binaries can be currently present in the Galaxy. The range of M-BH in them is about 4-10 M-circle dot, and the orbital periods are tens to hundreds of days. The unique black hole binary LB-1 fits well into this extremely rare class of double stars.