The Interaction of Asymptotic Giant Branch Stars with the Interstellar Medium

TL;DR

This paper investigates how gas expelled by moving Asymptotic Giant Branch stars interacts with the interstellar medium, revealing conditions for bow-shock and shell formation through hydrodynamical simulations.

Contribution

It presents detailed hydrodynamical models of AGB star winds interacting with the ISM, incorporating stellar evolution data and exploring various velocities, densities, and stellar masses.

Findings

Bow-shocks and cometary structures form under specific conditions.

Shell instabilities depend on relative velocities and ISM densities.

Results relate to different stellar populations in the Galaxy.

Abstract

We study the hydrodynamical behavior of the gas expelled by moving Asymptotic Giant Branch Stars interacting with the ISM. Our models follow the wind modulations prescribed by stellar evolution calculations, and we cover a range of expected relative velocities (10 to 100 km/s), ISM densities (between 0.01 and 1 cm-3), and stellar progenitor masses (1 and 3.5 Msun). We show how and when bow-shocks, and cometary-like structures form, and in which regime the shells are subject to instabilities. Finally, we analyze the results of the simulations in terms of the different kinematical stellar populations expected in the Galaxy.