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Simulation
of Bar-driven Spirals in Galactic Disks
It is well known that spiral density waves can be generated
by a rotating bar through a resonance excitation mechanism.
Associated with these waves is the angular momentum transport
between the bar and the disk. As waves attenuated by viscosity,
the angular momentum will be deposited in the disk. This will
cause the disk matter moving inward or outward, depending respectively
on whether the angular momentum carried by the waves is negative
or positive. The re-distribution of the matter of this kind
in the central gas-dust disk is recognized to be particularly
important, since it provides a mechanism of fueling AGN and
starburst ring activities. The morphology and dynamics of a
resonantly excited disk can be calculated analytically by non-linear
asymptotic methods in a steady state limit. However, the evolution
of the disk cannot be achieved unless we solve the full non-linear
equations in time.
On this webpage, we present numerical simulations of the disk
evolution, using the relaxation code we develop, for the following
three cases: spiral waves are generated by a bar.
Case
1: at the outer inner Lindblad resonance (OILR) 1.5 Kpc
Case
2: 3 Kpc-arm, single Lindblad resonance. OLR occures at 3 Kpc
Case
3: 3 Kpc-arm, double Lindblad resonance. OLR occures at 3 Kpc
and OILR occures at 0.7 Kpc.
All
of the results are computed in polar coordinates without self-gravitation.
All
Contents Copyright 1999-2003 CFD-MHD at ASIAA |
