出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：The dynamics of a barred galaxy depends on the pattern speed of its bar. The only direct method
for measuring the pattern speed of a bar is the Tremaine-Weinberg technique. This method relies
on the analysis of the distribution and dynamics of the stellar component. It is best suited to gaspoor
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. The complete sample of galaxies for which the bar pattern speed has been directly
measured with the Tremaine-Weinberg method is given. Nearly all the measured bars are as
rapidly rotating as they can be. By comparing this result 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.
