Observational studies of mass loss from AGB stars

TL;DR

This study investigates how metallicity affects the mass-loss rate of AGB stars by analyzing well-measured luminosities in Local Group galaxies using space telescope data, providing insights into stellar evolution and galactic matter cycles.

Contribution

It offers new empirical data on AGB star mass loss across different metallicities using galaxies with known distances, overcoming previous limitations of uncertain luminosities.

Findings

Mass-loss rates vary with metallicity in AGB stars.

AGB stars in lower-metallicity galaxies show different mass-loss characteristics.

Implications for stellar evolution and galactic chemical enrichment.

Abstract

It is important to properly describe the mass-loss rate of AGB stars, in order to understand their evolution from the AGB to PN phase. The primary goal of this study is to investigate the influence of metallicity on the mass-loss rate, under well determined luminosities. The luminosity of the star is a crucial parameter for the radiative driven stellar wind. Many efforts have been invested to constrain the AGB mass-loss rate, but most of the previous studies use Galactic objects, which have poorly known distances, thus their luminosities. To overcome this problem, we have studied mass loss from AGB stars in the Galaxies of the Local Group. The distance to the stars have been independently measured, thus AGB stars in these galaxies are ideal for understanding the mass-loss rate. Moreover, these galaxies have a lower metallicity than the Milky Way, providing an ideal target to study the influence of metallicity on the mass-loss rate. We report our analysis of mass loss, using the Spitzer Space Telescope and the Herschel Space Observatory. We will discuss the influence of AGB mass-loss on stellar evolution, and explore AGB and PN contribution to the lifecycle of matter in galaxies.