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, H. Sana, H. Beuther, A. Bik, W. Brandner, L. Kaper, H. Linz, Th. Henning and J. Poorta
