BLOeM. Projected rotational velocities

It will provide binary fractions and orbital configurations of binary systems, and search for dormant black-hole binary candidates (OB+BH). Here we present projected rotational velocities (vsini) of all sources and, using the multiplicity properties presented in previous papers, we derive the vsini distributions of apparent single stars, single lined spectroscopic (SB1) binaries, and SB2 systems.

We identify a locus in the Hertzsprung-Russell diagram where rotational velocities decrease significantly; we interpret this feature as broadly corresponding to the terminal-age main sequence. The main sequence cohort is distinguished by a broad range of vsini values, but with a strong peak in the distribution in the range 30-60km/s, close to the resolution limit of ~30km/s. Sources in this low vsini peak are distributed throughout the main sequence, and are also present in the SB1 sample, though less prominent than in the single star distribution.