| 標題主旨 |
講題: Bar-Driven Density Waves in the Central Regions of Galaxies
演講者：嚴健彰 (輔仁大學數學系)
Abstract:
Spiral density waves can be generated by a rotating bar
through a resonance excitation mechanism.
These waves are regarded as 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 is especially
important for the central gaseous disk,
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.
For that, we have to use numerical gasdynamics.
In this talk, we demonstrate three cases for the evolution
of a central gas-dust disk with the Antares code we develop.
Spiral waves are generated by a bar
(1) at the outer Lindblad resonance(OLR),
(2) at the inner Lindblad resonance (ILR),
and(3) both OLR and ILR are present.
These results show how the disk morphology changes and discuss the relevance
to the AGN and starburst ring activities in the center.
時間：2010年10月5日(星期二) 14：00 ∼ 16：00
地點：推廣大樓3樓9313室
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