C, SB1, SB2 and SB3 southern O stars rotation rate

The sample contains 130 spectroscopic single stars (C), 36 single-lined binaries (SB1), and 72 SB2 systems (including eight triples). We applied the Fourier method to high- resolution spectra taken at Cerro Murphy, Chile, and supplemented by archival spectra.

The overall vsini statistics peaks at slow rotators (40-100km/s) with a tail towards medium (100-200km/s) and fast rotators (200-400km/s). Binaries, on average, show increased rotation, which differs for close (Porb<10d) and wide binaries (10d<Porb<3700d), and for primaries and secondaries. The spin-up of close binaries is well explained by the superposition of spin-orbit synchronisation and mass transfer via Roche-lobe overflow.