Astronomy and Astrophysics – Astronomy
Scientific paper
Dec 2003
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003aas...20314609y&link_type=abstract
American Astronomical Society Meeting 203, #146.09; Bulletin of the American Astronomical Society, Vol. 36, p.591
Astronomy and Astrophysics
Astronomy
Scientific paper
Redistribution of the gas in a disk under the influence of a rotating bar potential is crucial to the understanding of the fuelling mechanism of AGNs and starburst ring activities. In this study, we simulate the evolution of a self-gravitating gas disk driven by a rapidly rotating central bar. Spiral density waves are excited at both the outer Lindblad resonance (OLR) and the outer inner Lindblad resonance (OILR). Associated with these waves are the angular momentum transports between the disk and the bar. As expected, the gas near the OLR gains angular momentum and moves out to form a ring, while near the OILR, the gas loses angular momentum and moves to the center. However, self-gravitation will cause spiral-ring structure at OLR unstable and developing chaos in the end, even with moderate bar forces. The instability occurs when Toomre's criterion is violated, i.e., Q<1. The instability is of gravitational origin, implying it may lead to starburst ring activities. The gas accumulated at the center, however, behaves normally, even with extremely high surface density. It is clear that the high values of epicyclic frequency or angular speed there provide sufficient inertia force to keep the nuclear gas disk from collapsing. We believe this is the reason why molecular or gas-dust disks are often found in the galactic center. We also find that Toomre's stability criterion, derived for axisymmetric disturbances, works extremely well for non-axisymmetric cases. We believe it is because at short wavelengths the stability is basically governed by Jeans criterion, insensitive to the azimuthal wavenumber m. We use the high-order Godunov codes we developed, with FFT Poisson solver. The work is supported in parts by a Key Project of Academia Sinica and National Science Council grant 91-2112-M-011-070.
Yen David C. C.
Yuan Changhe
No associations
LandOfFree
Evolution of a self-gravitating Gas Disk Driven by a Fast Bar in Normal Galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Evolution of a self-gravitating Gas Disk Driven by a Fast Bar in Normal Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evolution of a self-gravitating Gas Disk Driven by a Fast Bar in Normal Galaxies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1424152