Supermassive Black Holes and Kinematics of Disc Galaxies

TL;DR

This study investigates the relationship between supermassive black hole masses and the kinematic properties of disk galaxies, revealing strong correlations with central rotation velocities and total galaxy mass, suggesting SMBH growth during early galaxy formation.

Contribution

It demonstrates new correlations between SMBH masses and specific galaxy kinematic parameters, highlighting the role of central velocity and total mass in SMBH growth within disk galaxies.

Findings

SMBH masses correlate strongly with central rotation velocities at ~1 kpc.

Weak correlation between SMBH masses and asymptotic velocities at large radii.

Nuclear star cluster masses scale with total galaxy mass, especially in early-type disks.

Abstract

The statistical relations between the masses of supermassive black holes (SMBHs) in disk galaxies and the kinematic properties of their host galaxies are analyzed. We use the radial velocity profiles for several galaxies obtained earlier at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences parallel with the data for other galaxies taken from the literature. We demonstrate that the SMBH masses correlate well with the velocities of rotation of disks at a fixed distance R \approx 1 kpc (V1), which characterize the mean density of the central region of the galaxy. The SMBH masses correlate appreciably weaker with the asymptotic velocity at large distances from the center and with the angular velocity at the optical radius R_{25}. We suggest that the growth of the SMBH occurs inside of the forming "classical" bulge during a monolithic collapse of gas in the central kpc-size region of the protogalaxy. We have also found a correlation between the SMBH mass and the total (indicative) mass of the galaxy M_{25} within the optical radius R_{25}, which includes both baryonic and "dark" mass. The masses of the nuclear star clusters in early-type disk galaxies (based on the catalog of Seth et al.) are also scaled with the dynamical mass M_{25}, whereas the correlations with the luminosity and velocity of rotation of galaxies are practically absent for them. For a given M_{25} the masses of the nuclear clusters are, on average, nearly order of magnitude higher in S0-Sbc galaxies than in late-type galaxies.