Globular clusters as tracers of the dark matter content of dwarfs in galaxy clusters

ABSTRACT Globular clusters (GCs) are often used to estimate the dark matter content of galaxies, especially dwarf where other kinematic tracers lacking. These estimates typically assume spherical symmetry and dynamical equilibrium, assumptions that may not hold for sparse GC population dwarfs in galaxy clusters. We use a catalogue GCs tagged on Illustris simulation study accuracy GC-based mass estimates. focus galaxies stellar range 108–1011.8 M? identified nine simulated Virgo-like Our results indicate are, average, accurate systems with numbers NGC ? 10 uncertainty individual line-of-sight velocities is smaller than inferred velocity dispersion, ?GC. In cases ? 10, however, biases result, depending how ?GC computed. provide calibrations help alleviate these methods widely literature. As an application, we find number $M_{*} \sim 10^{8.5}\, \mathrm{M}_{\odot }$ – comparable ultra-diffuse 1052-DF2 (DF2), notable low its have $\sigma _{\rm GC} 7\!-\!15\, {\rm km \,s}^{-1}$. DF2 analogues correspond relatively massive at their infall time (M200 ? 1–3 × 1011 M?), which retained only 3–17 been stripped more 95 per cent matter. suggest extreme tidal loss otherwise normal be possible formation channel objects such as DF2.