  Recent studies have suggested a strong correlation between the masses of
nuclear star clusters and their host galaxies, an extension of the known
correlations between supermassive black holes (SMBHs) and their host galaxies.
By focusing on disk galaxies with well-determined black hole and nuclear
cluster masses, we argue that there is not a universal "central massive object"
correlation after all: careful analysis shows that while SMBHs correlate better
with the stellar masses of the bulge components, nuclear star clusters clearly
correlate better with total galaxy stellar mass.
