The physics governing the upper truncation mass of the globular cluster mass function

The mass function of globular cluster (GC) populations is a fundamental observable that encodes the physical conditions under which these massive stellar clusters formed and evolved. The high-mass end of star cluster mass functions are commonly described using a Schechter function, with an exponential truncation mass M-c, (*). For the GC mass functions in the Virgo galaxy cluster, this truncation mass increases with galaxy mass (M-*). In this paper, we fit Schechter mass functions to the GCs in the most massive galaxy group (M-200 = 5.14 x 10(13) M-circle dot) in the E-MOSAICS simulations. The fiducial cluster formation model in F.-MOSAICS reproduces the observed trend of M-c, (*) with M-* for the Virgo cluster. We therefore examine the origin of the relation by fitting M-c, (*). as a function of galaxy mass, with and without accounting for mass loss by two-body relaxation, tidal shocks and/or dynamical friction. In the absence of these mass-loss mechanisms, the M-c, (*) .-M-* relation is flat above M-* > 10(10) M-circle dot. It is therefore the disruption of high-mass GCs in galaxies with M-* similar to 10(10) M-circle dot that lowers the M-c, (*) in these galaxies. High-mass GCs are able to survive in more massive galaxies, since there are more mergers to facilitate their redistribution to less-dense environments. The M-c, (* )- M-* relation is therefore a consequence of both the formation conditions of massive star clusters and their environmentally dependent disruption mechanisms.