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

TL;DR

This paper discusses methods for measuring the pattern speed of bars in early-type galaxies, emphasizing the Tremaine-Weinberg technique and its implications for understanding galaxy dynamics and dark matter content.

Contribution

It compares direct and indirect methods for measuring bar pattern speeds and analyzes their implications for galaxy structure and dark matter distribution.

Findings

Tremaine-Weinberg method is effective for early-type galaxies.

Most bars are rapidly rotating, indicating maximal disks.

Bar pattern speeds provide insights into dark matter content.

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.