Recent advances on IMF research

Abstract

Here I discuss recent work on brown dwarfs, massive stars and the IMF in general, which are areas of research to which Anthony Whitworth has been contributing major work. The stellar IMF can be well described by an invariant two-part power law in present-day star-formation events (SFevs) within the Local Group of galaxies. It is nearly identical in shape to the pre-stellar core mass function (André, A&A 518:L102, 2010). The majority of brown dwarfs follow a separate IMF. Evidence from globular clusters and ultra-compact dwarf galaxies has emerged that IMFs may have been top heavy depending on the star-formation rate density (Marks et al., MNRAS 422:2246, 2012). The IGIMF then ranges from bottom heavy at low galaxy-wide star formation rates to being top-heavy in galaxy-scale star bursts.