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OATS-DAUT SEMINAR
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Speaker:
Enrico Maria Corsini (Univ. di Padova)
Title:
Dark matter distribution and gas fueling in the center of barred
galaxies
Date: Wednesday, November 15th, 2006
Time: 12:00 noon
Venue: Villa Bazzoni
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Abstract:
The dynamics of a barred galaxy depends on the
pattern speed of its bar. The only direct method for measuring the bar
pattern speed is the Tremaine-Weinberg technique. This method is best
suited to gas-poor galaxies and therefore it has been restricted to
early-type barred galaxies. On the other hand, a variety of indirect
methods, which are based on the analysis of the distribution and
dynamics of the gaseous component, has been used to measure the bar
pattern speed in late-type barred galaxies. Nearly all the measured
bars are as rapidly rotating as they can be. By comparing these
results with recent high-resolution N-body simulations of bars in
cosmologically-motivated dark matter halos, it is possible to conclude
that these bars are not located inside centrally-concentrated
halos. The Tremaine-Weinberg technique also permitted us to establish
directly that nested bars are rotating with different pattern speeds
and, in particular, that the rotation frequency of the secondary bar
is higher than that of the primary one. This makes double bars
efficient agents in fueling the AGN activity.
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