29 août 2019
Star formation is a multi-physics, multi-scale process. the physical scales that are involved vary by 10 orders of magnitude, from the size of entire galaxies down to the size of the Solar system. The physical processes that are involved include gravity, turbulence, magnetic fields, radiation, chemical reactions, and cooling and heating processes. This multiplicity of processes and scales can generate a significant amount of variation in the outcome of star formation from galaxy to galaxy and from region to region within galaxies, in particular in terms of key quantities such as the stellar initial mass function (IMF), the star formation rate (SFR), and the star formation efficiency (SFE). I will present a brief overview of the current status of observations for the IMF and the SFR in the Milky Way and in nearby galaxies and discuss theoretical ideas and numerical simulations that attempt to reproduce these observations.