The theory of stellar winds

TL;DR

This paper reviews the theory of stellar winds, focusing on radiation-driven outflows from massive stars, their impact on stellar evolution, and the importance of opacity data for accurate modeling.

Contribution

It provides a comprehensive overview of radiation-driven stellar wind theory, emphasizing the role of metallicity, temperature, and opacity data in mass-loss predictions and stellar evolution.

Findings

Mass-loss rates depend on metallicity and temperature.

The bi-stability jump significantly affects stellar wind properties.

Opacity data critically influence wind models and stellar evolution understanding.

Abstract

We present a brief overview of the theory of stellar winds with a strong emphasis on the radiation-driven outflows from massive stars. The resulting implications for the evolution and fate of massive stars are also discussed. Furthermore, we relate the effects of mass loss to the angular momentum evolution, which is particularly relevant for the production of long and soft gamma-ray bursts. Mass-loss rates are not only a function of the metallicity, but are also found to depend on temperature, particularly in the region of the bi-stability jump at 21 000 Kelvin. We highlight the role of the bi-stability jump for Luminous Blue Variable (LBV) stars, and discuss suggestions that LBVs might be direct progenitors of supernovae. We emphasize that radiation-driven wind studies rely heavily on the input opacity data and linelists, and that these are thus of fundamental importance to both the mass-loss predictions themselves, as well as to our overall understanding of the lives and deaths of massive stars.