Observational constraints on stellar feedback in dwarf galaxies

TL;DR

This paper reviews recent observational evidence on how stellar feedback from ionising radiation, winds, and supernovae influences dwarf galaxy evolution, affecting their star formation, structure, and dark matter content.

Contribution

It provides a comprehensive summary of observational constraints on stellar feedback processes in dwarf galaxies and discusses their implications for galaxy formation theories.

Findings

Feedback drives superbubbles and galaxy winds.

External ionising radiation impacts the smallest galaxies.

Feedback influences galaxy properties like star formation and dark matter densities.

Abstract

Feedback to the interstellar medium (ISM) from ionising radiation, stellar winds and supernovae is central to regulating star formation in galaxies. Due to their low mass ($M_{*} < 10^{9}$\,M$_\odot$), dwarf galaxies are particularly susceptible to such processes, making them ideal sites to study the detailed physics of feedback. In this perspective, we summarise the latest observational evidences for feedback from star forming regions and how this drives the formation of 'superbubbles' and galaxy-wide winds. We discuss the important role of external ionising radiation -- 'reionisation' -- for the smallest galaxies. And, we discuss the observational evidences that this feedback directly impacts galaxy properties such as their star formation histories, metal content, colours, sizes, morphologies and even their inner dark matter densities. We conclude with a look to the future, summarising the key questions that remain unanswered and listing some of the outstanding challenges for galaxy formation theories.