Description
We present a post-processing catalog of globular clusters (GCs) for the 39 most massive galaxy groups and clusters (M$_{200} = [5\times 10^{12} - 2\times 10^{14}] \ \rm M_{\odot}$) in the TNG50 simulation. We tag GCs particles to all galaxies with stellar masses $M_{\odot} \geq 5\times 10^{6} \ \rm M_{\odot}$, and we calibrate the total mass of the GC system to reproduce the observed GC mass-halo mass relation for galaxies with M$_{200} \geq 10^{11} \ \rm M_{\odot}$ (corresponding to M$_* \sim 10^{9} \ \rm M_{\odot}$). Here, we explore whether an extension of the GC-mass halo mass relation to lower-mass dwarfs is consistent with current observations. We find good agreement between our predicted number and specific frequency of GCs in dwarfs with $\rm M_{*} = [5\times 10^6 - 10^9] \ \rm M_{\odot}$ and observations. Moreover, we predict a steep decline in the GC occupation fraction for dwarfs with M$_* \leq 10^{9} \ \rm M_{\odot}$, which agrees well with observational constraints.This declining occupation fraction is due to a combination of tidal stripping in all dwarfs plus a stochastic sampling of the GC mass function for dwarfs with M$_* < 10^{7.5} \ \rm M_{\odot}$. Our simulations also reproduce available constraints on the abundance of intra-cluster GCs in Virgo and Centaurus A. These successes provide support to the hypothesis that the $M_{\rm GC}$-$M_{200}$ relation holds, albeit with more scatter, all the way down to the regime of classical dwarf spheroidals in these environments.
