The VLT-FLAMES Tarantula Survey XXI. Stellar spin rates of O-type spectroscopic binaries

摘要: The initial distribution of spin rates massive stars is a fingerprint their elusive formation process. It also sets key condition for stellar evolution and thus an important ingredient in population synthesis. So far, most studies have focused on single stars. Most O are however found multiple systems. By establishing the spin-rate sizeable sample O-type spectroscopic binaries by comparing distributions binary sub-populations with one another as well that presumed same region, we aim to constrain binaries, identify signatures physical mechanisms affect rates. We use ground-based optical spectroscopy obtained framework VLT-FLAMES Tarantula Survey (VFTS) establish projected equatorial rotational velocities (\vrot) components 114 30 Doradus. \vrot\ values derived from full-width at half-maximum (FWHM) set spectral lines, using FWHM vs. calibration derive based previous line analysis methods applied VFTS sample. overall primary resembles VFTS, featuring low-velocity peak (at $\vrot < 200$ kms) shoulder intermediate ($200 \vrot 300$ kms). differ two ways. First, main \sim$100 kms broader slightly shifted toward higher compared presumed-single Second, primaries lacks significant spinning faster than 300 while such clearly present star