Supermassive black holes and central star clusters: Connection with the host galaxy kinematics and color

The relationship between the masses of the central, supermassive black holes ( M bh ) and of the nuclear star clusters ( M nc ) of disk galaxies with various parameters galaxies are considered: the rotational velocity at R = 2 kpc V (2) , the maximum rotational velocity V max , the indicative dynamical mass M 25 , the integrated mass of the stellar population M * , and the integrated color index B-V . The rotational velocities andmasses of the central objects were taken from the literature. Themass M nc correlatesmore closely with the kinematic parameters and the disk mass than M bh , including with the velocity V max , which is closely related to the virial mass of the dark halo. On average, lenticular galaxies are characterized by higher masses M bh compared to other types of galaxies with similar characteristics. The dependence of the blackhole mass on the color index is bimodal: galaxies of the red group (red-sequence) with B-V >0.6–0.7 which are mostly early-type galaxies with weak star formation, differ appreciably from blue galaxies, which have higher values of M nc and M bh . At the dependences we consider between the masses of the central objects and the parameters of the host galaxies (except for the dependence of M bh on the central velocity dispersion), the red-group galaxies have systematically higher M bh values, even when the host-galaxy parameters are similar. In contrast, in the case of nuclear star clusters, the blue and red galaxies form unified sequences. The results agree with scenarios in which most red-group galaxies form as a result of the partial or complete loss of interstellar gas in a stage of high nuclear activity in galaxies whose central black-hole masses exceed 10 6 −10 7 M ⊙ (depending on the mass of the galaxy itself). The bulk of disk galaxies with M bh > 10 7 M ⊙ are lenticular galaxies (types S0, E/S0) whose disks are practically devoid of gas.