The Rotation of Bulges

TL;DR

This paper reviews the dynamical properties of galactic bulges, emphasizing the importance of structural analysis, and presents kinematic results indicating that exponential bulges are more rotationally supported than those with higher Sersic indexes.

Contribution

It provides new kinematic measurements of bulges in edge-on galaxies and highlights the significance of structural analysis in interpreting bulge rotation.

Findings

Exponential bulges show higher rotational support.

Structural analysis is crucial for accurate kinematic measurements.

Different Sersic index bulges may belong to distinct stellar systems.

Abstract

I briefly review early and recent progress concerning the dynamical properties of bulges. I also show results from a study on the kinematics of bulges and disks in edge-on galaxies, where the bulge rotation curve is obtained with little contamination from the disk. I show that a proper structural analysis is crucial to understand such measurements. The results suggest that exponential bulges have a higher degree of rotational support than bulges with higher Sersic indexes, giving support to the concept that photometric bulges include different categories of stellar systems.