Abstract
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 $10^{8.5} \,{{{M}_{\odot}}}$ 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.
Highlights
Recent observations indicate that massive central black holes exist in disk galaxies as well as in ellipticals
We have shown that a massive central black hole (BH) can dissolve a bar within a short time scale if the BH is as massive as about 0.5% of the disk mass
This means that the minimum BH mass necessary for bar dissolution would be of order 108.5M⊙ for a typical disk galaxy
Summary
Recent observations indicate that massive central black holes exist in disk galaxies as well as in ellipticals. Remarkable as their result is, the implied mass for bar destruction becomes about 109.5M⊙ when scaled to a typical disk galaxy with a mass ∼ 1010.5 − 1011M⊙ If this mass concentration is associated with a central black hole, the required BH mass is greater than that inferred in nearby spirals and is comparable to the largest BH masses derived observationally in ellipticals. That in at least some cases the minimum black hole mass for bar destruction may be at least a factor of ten smaller than that suggested by the work of Norman et al (1996) This is not necessarily in conflict with the conclusions of Norman et al, since they modeled the consequences of the build-up of gas concentrations in the inner regions of a barred disk, while we are interested in the influence of a central black hole
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