S316p.06 — Nuclear Star Clusters in late- and early-type galaxies and coexsiting with massive black holes

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Aug 10th at 6:00 PM until 7:30 PM

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Author(s): Iskren Y. Georgiev1

Institution(s): 1. Max Plank Isntitute for Astronomy

Here we explore scaling relations between NSC mass and size (M_NSC) and host galaxy total stellar mass, M_gal, and galaxy morphology based on a large sample of NSCs in late- and early-type galaxies, including a sample of coexisting NSCs and massive black holes (MBHs). Such scaling relations bare important information for the mechanisms driving the formation and (co)evolution of these central massive objects. We observe statistically significant different slopes and offsets between NSCs in late- and early-types hosts in their scaling relations for reff,NSC–M_NSC, reff,NSC–M_gal and M_NSC–M_gal. We find that i) NSCs in late-types appear more compact (0.2 dex) at fixed M_NSC and M_gal; ii) the M_NSC–M_gal relation is shallower for NSCs in late-types than for early-types, but interestingly, similar to the M_BH–M_bulge relation. Possible biases are insufficient to entirely account for observed differences and we discuss possible evolutionary effects of NSC growth (cluster merging and/or funneling gas to nucleus, passive/active mass evolution of host galaxy mass). For the coexisting NSC-MBH systems we find M_BH/M_NSC ratio to range from 0.01% to >> 100% from low- to high-mass galaxies. To assess the influence of a MBH to more than 50% of the MNSC, we take the ratio between the radius of the MBH sphere of influence and the NSC effectife radius and discuss it in the light of the coexistence of NSCs and MBHs.