Populations of OB-type stars in galaxies

TL;DR

This paper reviews recent studies of OB-type stars across different galaxies, highlighting their role in understanding stellar evolution, galaxy chemistry, and dynamics, especially in high-redshift, star-forming environments.

Contribution

It synthesizes observational and theoretical insights into massive stars in various environments, aiding spectral synthesis of unresolved stellar populations in distant galaxies.

Findings

Massive stars in the Galaxy and Magellanic Clouds provide key insights into environmental effects on stellar evolution.

Observations of luminous supergiants out to 6.7 Mpc help study galaxy chemistry and dynamics.

Understanding of stellar evolution improves spectral analysis of high-redshift, star-forming galaxies.

Abstract

One of the challenges for stellar astrophysics is to reach the point at which we can undertake reliable spectral synthesis of unresolved populations in young, star-forming galaxies at high redshift. Here I summarise recent studies of massive stars in the Galaxy and Magellanic Clouds, which span a range of metallicities commensurate with those in high-redshift systems, thus providing an excellent laboratory in which to study the role of environment on stellar evolution. I also give an overview of observations of luminous supergiants in external galaxies out to a remarkable 6.7 Mpc, in which we can exploit our understanding of stellar evolution to study the chemistry and dynamics of the host systems.