Collisionless Boltzmann equation approach for the study of stellar discs within barred galaxies

TL;DR

This paper develops a numerical approach to solve the 2D2V Collisionless Boltzmann Equation for stellar discs, revealing bar pattern speeds and structures in the Milky Way's solar neighborhood with reduced noise compared to N-body simulations.

Contribution

The study introduces a numerical resolution of the 2D2V Collisionless Boltzmann Equation to analyze stellar kinematics, providing detailed insights into the Galactic bar's properties.

Findings

Bar pattern speed ratio $rac{\

Bar pattern speed between 46 and 49 km/s/kpc

Faint structures identified due to noise cancellation

Abstract

We study the kinematics of stellar disc populations within the solar neighbourhood in order to find the imprints of the Galactic bar. We carry out the analysis by developing a numerical resolution of the 2D2V Collisionless Boltzmann Equation (CBE) and modelling the stellar motions within the plane of the Galaxy within the solar neighbourhood. We recover similar results to these obtained by different authors using N-body simulations, but we can also numerically identify faint structures thanks to the canceling of the Poisson noise. We find that the ratio of the bar pattern speed to the local circular frequency is in the range $\Omega_B/\Omega$ = 1.77 to 1.91. If the Galactic bar angle orientation is within the range from 24 to 45 degrees, the bar pattern speed is between 46 and 49 km/s/kpc.