Introducing AuriGLOBES: The effects of compressive tides, compact object-induced mass loss, and size evolution on modelling globular clusters

Abstract

Globular clusters (GCs) are long time survivors of galaxy assembly and evolution yet their emergence from an initial cluster population is still poorly constrained. We present the Auriga GLOBular clustEr Simulations (AuriGLOBES) a physically motivated subgrid model for star cluster (SC) formation and evolution that includes enhanced mass loss from compact object remnants. With this model, implemented in the Auriga cosmological galaxy formation model, we run a suite of zoom-in cosmological simulations comprising 9 Milky Way mass and 5 lower mass galaxies. We demonstrate that our model produces plausible GC populations compared to the Milky Way/M31 systems and reproduces the empirical GC system mass -- halo mass relation within a 2$\sigma$ scatter. We show that the formation of SCs in tidally compressive, high-pressure gas in addition to enhanced mass loss from compact object remnants heating is required to capture the transformation of an initial Schechter mass function to the characteristic observed GC mass function in the Milky Way/M31 systems. The resulting GC populations show spatial and metallicity distributions qualitatively similar to the Milky Way/M31 systems, as well as a variety of age distributions that correlate with the star formation history of the simulated galaxies. However, the peak of the age distribution of Milky Way GCs is older than any of our simulated Milky Way-mass galaxies, which is attributed to unrepresented star formation and galaxy assembly histories. AuriGLOBES represents a reliable framework for the study of GC populations through cosmic history and a robust foundation for future applications for a model of stellar streams arising from GCs disruption.