Spitzer observations of molecules and dust in evolved stars in nearby galaxies

TL;DR

This paper discusses how Spitzer Space Telescope observations of molecules and dust in evolved stars across nearby galaxies enhance understanding of stellar contributions to galactic chemical evolution, especially considering varying metallicities.

Contribution

It provides the first quantitative analysis of molecules and dust in evolved stars in nearby galaxies, highlighting the impact of metallicity on dust and gas production.

Findings

Enabled study of dust and molecules in stars beyond our Galaxy.

Showed metallicity influences dust and gas production in evolved stars.

Contributes to understanding galaxy chemical evolution across metallicities.

Abstract

Molecules and dust are formed in and around the asymptotic giant branch (AGB) stars and supernovae (SNe), and are ejected into the interstellar medium (ISM) through the stellar wind. The dust and gas contain elements newly synthesised in stars, thus, dying stars play an important role on chemical enrichment of the ISM of galaxies. However, quantitative analysis of molecules and dust in these stars had been difficult beyond our Galaxy. The high sensitivity instruments on board the Spitzer Space Telescope have enabled us to study dust and molecules in these stars in nearby galaxies. Nearby galaxies have wide range of metallicities, thus the impact of the metallicity on dust and gas production can be studied. This study will be useful for chemical evolution of galaxies from low to high metallicities.