GRAVITATIONAL STABILITY OF CIRCUMNUCLEAR DISKS IN ELLIPTICAL GALAXIES

摘要: A significant fraction of nearby elliptical galaxies are known to have high-density gas disks in their circumnuclear (CN) region (0.1 a few kpc). Yet ellipticals, especially luminous ones, show little sign recent star formation. To investigate the possible cause dearth formation these systems, we study gravitational stability CN embedded within potentials both stellar bulge component and central massive black hole (BH) galaxies. We find that higher mass generally more stable than those lower galaxies, because tend BHs centrally concentrated density profiles. also consider case which profile has core, is often observed for ellipticals whose total about 1011 M☉. Such cored leads unstable power-law characteristic less However, high-mass act stabilize disk. Our results demonstrate BH should be taken into account when studying properties disks, as sensitive profile. could explain trend greater tendency exhibit ongoing giant ellipticals.