Recent advances on IMF research

TL;DR

This paper reviews recent research on the stellar initial mass function (IMF), highlighting its invariance in local star formation, variations in brown dwarfs, and potential top-heavy IMFs in intense starburst environments.

Contribution

It synthesizes recent findings on IMF characteristics across different stellar populations and environments, emphasizing possible variations linked to star formation activity.

Findings

IMF is well described by a two-part power law in local star formation.

Brown dwarfs follow a separate IMF from stars.

IMFs may be top-heavy in high star-formation rate environments.

Abstract

Here I discuss recent work on brown dwarfs, massive stars and the IMF in general. The stellar IMF can be well described by an invariant two-part power law in present-day star-formation events within the Local Group of galaxies. It is nearly identical in shape to the pre-stellar core mass function. 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. The IGIMF then ranges from bottom heavy at low galaxy-wide star formation rates to being top-heavy in galaxy-scale star bursts.