Compact nuclear objects and properties of their parent galaxies
  We consider the relationship between the masses of the compact nuclear
objects in the centers of disky galaxies -- supermassive black holes (SMBHs) or
nuclear star clusters (NCs) -- and such parameters as the maximal velocity of
rotation $V_{\textrm{max}}$, obtained from the rotation curves, indicative
dynamical mass $M_{25}$, and the color index ($B{-}V$) of their parent
galaxies. It was found that the mass of nuclear clusters $M_{\rm nc}$
correlates more closely with the velocity of rotation and total mass of
galaxies than the mass of supermassive black holes $M_{\rm bh}$. The dependence
of masses of the central objects on the color index is bimodal: galaxies of the
red group (red-sequence), which have ($B{-}V) > 0.6{-}0.7$, differ from bluer
galaxies, by higher values of $M_{\rm bh}$ for similar host-galaxy parameters.
In contrast, in the diagrams for nuclear clusters the "blue" and "red" galaxies
form unified sequences. It agrees with scenarios in which most red-group
galaxies form as a result of loss of interstellar gas in a stage of high
nuclear activity in galaxies whose central black-hole masses are high,
exceeding $10^6 {-} 10^7 M_{\odot}$ (depending on the total mass of the
galaxy). The active growth of nuclear star clusters possibly begun after the
violent AGN activity.
