English

The systematically varying stellar IMF

Astrophysics of Galaxies 2020-03-18 v1

Abstract

Some ultra-compact dwarf galaxies have large dynamical mass to light (M/L) ratios and also appear to contain an overabundance of LMXB sources, and some Milky Way globular clusters have a low concentration and appear to have a deficit of low-mass stars. These observations can be explained if the stellar IMF becomes increasingly top-heavy with decreasing metallicity and increasing gas density of the forming object. The thus constrained stellar IMF then accounts for the observed trend of metallicity and M/L ratio found amongst M31 globular star clusters. It also accounts for the overall shift of the observationally deduced galaxy-wide IMF from top-light to top-heavy with increasing star formation rate amongst galaxies. If the IMF varies similarly to deduced here, then extremely young very massive star-burst clusters observed at a high redshift would appear quasar-like (Jerabkova et al. 2017) .

Keywords

Cite

@article{arxiv.1910.06971,
  title  = {The systematically varying stellar IMF},
  author = {Pavel Kroupa},
  journal= {arXiv preprint arXiv:1910.06971},
  year   = {2020}
}

Comments

Appearing in the proceedings of IAUS351 on Star Clusters: From the Milky Way to the Early Universe, held in Bologna, May 27th-31st

R2 v1 2026-06-23T11:44:38.707Z