High M/L ratios of UCDs: a variation of the IMF?

TL;DR

This paper explores whether variations in the initial mass function (IMF) can explain the unusually high mass-to-light ratios observed in ultra-compact dwarf galaxies, and discusses observational strategies to test this.

Contribution

It proposes that IMF variations could account for high M/L ratios in UCDs and outlines observational methods to distinguish this from other explanations.

Findings

IMF variations may explain high M/L ratios in UCDs

Observational approaches can discriminate between IMF variations and dark matter presence

Discussion of dark matter's role in UCDs

Abstract

Various studies have established that the dynamical M/L ratios of ultra-compact dwarf galaxies (UCDs) tend to be at the limit or beyond the range explicable by standard stellar populations with canonical IMF. We discuss how IMF variations may account for these high M/L ratios and how observational approaches may in the future allow to discriminate between those possibilities. We also briefly discuss the possibility of dark matter in UCDs.