Nuclear star clusters photometric masses

In the intermediate-mass range, some nuclei host both an NSC and an MBH. In this paper, we explore scaling relations between NSC mass (M_*,gal_) and host-galaxy total stellar mass (M_NSC_) using a large sample of NSCs in late- and early-type galaxies, including a number of NSCs harbouring an MBH.

Such scaling relations reflect the underlying physical mechanisms driving the formation and (co)evolution of these central massive objects. We find ~1.5{sigma} significant differences between NSCs in late- and early-type galaxies in the slopes and offsets of the relations r_eff,NSC_-M_NSC_, r_eff,NSC_-M_*,gal_ and M_NSC_-M_*,gal_, in the sense that (i) NSCs in late types are more compact at fixed M_NSC_ and M_*,gal_; and (ii) the M_NSC_-M_*,gal_ relation is shallower for NSCs in late types than in early types, similar to the M_BH-M_*,bulge relation.