On the formation of star clusters in self-gravitating molecular clouds

Abstract: In the Milky Way, for stars to form, self-gravitating cold molecular gas must collapse. But the question is how much? Current star formation theories have very large discrepancies regarding the dynamical state of molecular clouds, some predicting that only their most compact over-densities (i.e. the cores < 0.1pc) are bound and collapsing, while others propose that clouds collapse as a whole over several tens of parsecs. In this presentation, I will review some of the recent observational results that my collaborators and I have put forward on the dynamical state of molecular clouds. Those results draw a picture in which clumps, i.e. the progenitors of star clusters, are systematically collapsing, while their parent molecular clouds are not. In addition, we find evidence of a link between massive core formation and the dynamical evolution of those clumps, but the extreme complexity of the inner clump velocity fields makes it hard to identify individual core-forming accretion flows.