Dynamical effects of the long bar in the Milky Way

TL;DR

This study models the dynamical influence of the Milky Way's long bar on disk stars, revealing minor but notable orbital shifts and redistributions within the galaxy's inner regions.

Contribution

Introduces a simulation of a long, rotating bar's effects on disk star dynamics, providing insights into its role in galactic structure formation.

Findings

The long bar causes slight orbital shifts in nearby stars.

Stars near the bar are redistributed into the bar and bulge regions.

The overall impact on the disk system is modest but significant.

Abstract

We examine the dynamical effects on disk stars of a "long bar" in the Milky Way by inserting a triaxial rotating bar into an axisymmetric disk+bulge+dark halo potential and integrating 3-D orbits of 104 tracer stars over a period of 2 Gyr. The long bar has been detected via "clump giants" in the IR by Lopez-Corredoira et al. (2007), and is estimated to have semi-major axes of (3.9 : 0.6 : 0.1) kpc and a mass of 6 10^9 Msun. We find such a structure has a slight impact on the inner disk-system, moving tracers near to the bar into the bar-region, as well as into the bulge. These effects are under continuing study.