Globular Cluster-like Dwarf Galaxies in Cold and Warm Dark Matter

The fundamental nature of dark matter is critical to understanding the formation of dark matter halos and the galaxies they host. Due to being extremely dark matter dominated, dwarf galaxies provide an ideal astrophysical environment with which to study the nature of dark matter on galactic scales. While cold dark matter (CDM) has been the leading model of structure formation, warm dark matter (WDM) candidates predict a lack of structure on sub-galactic scales. By studying the smallest dwarf galaxies, we can therefore provide cutting-edge constraints on warm dark matter properties. In this project, we utilize the high resolution Engineering Dwarfs at Galaxy’s Edge (EDGE) simulation suite to study the cosmological formation of globular cluster-like dwarf galaxies (GCDs)—a new class of objects that share traits of both dwarf galaxies and globular clusters. Like dwarf galaxies, these objects form in dark matter halos, yet have small age dispersions similar to globular clusters. We analyze GCDs with stellar masses of ~10² and halo masses between ~10⁶ and 10⁷, and present their observable properties, including their V-band magnitudes, metallicity ratios and spread, and age spreads. We show that the abundance of GCDs and their ages may place some of the strongest constraints on WDM to date.