Secular Evolution of Barred Galaxies with Massive Central Black Holes

Abstract

The influence of central black holes on the dynamical evolution of bars in disk galaxies was examined. Once a bar formed by a dynamical instability in an infinitesimally thin stellar disk was fully developed, a black hole (BH) was adiabatically added at the center of the disk. Our results indicate that a bar can be completely destroyed, in a practical sense, in a time much smaller than the Hubble time if the central BH mass exceeds about 0.5% of the disk mass. Since this implied minimum BH mass for bar destruction is on the order of 10(8.5) Me for a typical disk galaxy, this process could occur in the real Universe. The bar amplitude decreases gradually with time after the BH has grown up to its full mass. Surface-of-section plots indicate that the bar dissolution originates from the chaotic behavior of bar-supporting orbits. In addition, the scale length and the radial velocity dispersion of the disk after bar dissolution become much larger than those of the initial axisymmetric disk. This finding suggests that it is. possible to discriminate between genuine non-barred galaxies and bar-dissolved galaxies induced by massive central BHs from the viewpoint of structural properties.