Primordial mass segregation of star clusters: The role of binary stars
  Observational results of young star-forming regions suggest that star
clusters are completely mass segregated at birth. As a star cluster evolves
dynamically, these initial conditions are gradually lost. For star clusters
with single stars only and a canonical IMF, it has been suggested that traces
of these initial conditions vanish at $\tau_{\rm v}$ between 3 and 3.5
half-mass relaxation times. By the means of numerical models, here we
investigate the role of the primordial binary population on the loss of
primordial mass segregation. We found that $\tau_{\rm v}$ does not seem to
depend on the binary star distribution, yielding $3 < \tau_{\rm v} / t_{\rm rh}
< 3.5$. We also conclude that the completely mass segregated clusters, even
with binaries, are more compatible with the present-day ONC than the
non-segregated ones.
