Popis: |
We model the Galactic population of detached binaries that harbor black holes with (0.5-1.7) solar mass companions -- the 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 black hole masses in them is about 4 to 10 solar ones, the orbital periods are tens to hundreds day. The unique BH-binary LB-1 fits well into this extremely rare class of double stars. Comment: 5 pp., 6 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society Letters |