Abstract

Using deep, high-resolution optical imaging from the Next Generation Virgo Cluster Survey, we study the properties of nuclear star clusters (NSCs) in a sample of nearly 400 quiescent galaxies in the core of Virgo with stellar masses 10(5) less than or similar to M-*/M-circle dot less than or similar to 10(12). The nucleation fraction reaches a peak value f(n) approximate to 90% for M-* approximate to 10(9) M-circle dot galaxies and declines for both higher and lower masses, but nuclei populate galaxies as small as M-* approximate to 5 x 10(5) M-circle dot. Comparison with literature data for nearby groups and clusters shows that at the low-mass end nucleation is more frequent in denser environments. The NSC mass function peaks at M-NSC approximate to 7 x 10(5) M-circle dot, a factor 3-4 times larger than the turnover mass for globular clusters (GCs). We find a nonlinear relation between the stellar masses of NSCs and those of their host galaxies, with a mean nucleus-to-galaxy mass ratio that drops to M-NSC/M-* approximate to 3.6 x 10(-3) for M-* approximate to 5 x 10(9) M-circle dot galaxies. Nuclei in both more and less massive galaxies are much more prominent: M-NSC proportional to M-*(0.46) at the low-mass end, where nuclei are nearly 50% as massive as their hosts. We measure an intrinsic scatter in NSC masses at a fixed galaxy stellar mass of 0.4 dex, which we interpret as evidence that the process of NSC growth is significantly stochastic. At low galaxy masses we find a close connection between NSCs and GC systems, including very similar occupation distributions and comparable total masses. We discuss these results in the context of current dissipative and dissipationless models of NSC formation.