Bulge properties and dark matter content of early-type barred galaxies

Abstract

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 is best suited to the analysis of the distribution and dynamics of the stellar component. Therefore it has been mostly used for early-type barred galaxies. Most of them host a classical bulge. 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 this result with high-resolution numerical simulations of bars in dark matter halos, it is possible to conclude that these bars reside in maximal disks.