A relation between the radial velocity dispersion of young clusters and their age: Evidence for hardening as the formation scenario of massive close binaries

M. C. Ramírez-Tannus, F. Backs, A. de Koter +8

The majority of massive stars ($>8$ ${\mathrm{M}}_{\odot }$) in OB associations are found in close binary systems. Nonetheless, the formation mechanism of these close massive binaries is…