ELVES II: GCs and Nuclear Star Clusters of Dwarf Galaxies; The
  Importance of Environment
  We present the properties of the globular clusters (GCs) and nuclear star
clusters (NSCs) of low-mass ($10^{5.5}<M_\star<10^{8.5}$ $M_\odot$) early-type
satellites of Milky Way-like and small group hosts in the Local Volume (LV)
using deep, ground-based data from the ongoing Exploration of Local VolumE
Satellites (ELVES) Survey. This sample of 177 dwarfs significantly increases
the statistics for studying the star clusters of dwarfs in low-density
environments, offering an important comparison to samples from nearby galaxy
clusters. The LV dwarfs exhibit significantly lower nucleation fractions at
fixed galaxy mass than dwarfs in nearby clusters. The mass of NSCs of LV dwarfs
show a similar scaling of $M_{\star,\mathrm{NSC}}\propto
M_{\star,\mathrm{gal}}^{0.4}$ as that found in clusters but offset to lower NSC
masses. To deal with foreground/background contamination in the GC analysis, we
employ both a statistical subtraction and Bayesian approach to infer the
average GC system properties from all dwarfs simultaneously. We find that the
GC occupation fraction and average abundance are both increasing functions of
galaxy stellar mass, and the LV dwarfs show significantly lower average GC
abundance at fixed galaxy mass than a comparable sample of Virgo dwarfs
analyzed in the same way, demonstrating that GC prevalence also shows an
important secondary dependence on the dwarf's environment. This result
strengthens the connection between GCs and NSCs in low-mass galaxies. We
discuss these observations in the context of modern theories of GC and NSC
formation, finding that the environmental dependencies can be well-explained by
these models.
