ISM enrichment and local pollution in dwarf galaxies

TL;DR

This paper reviews how metals produced in starburst episodes are distributed within dwarf galaxies, focusing on the phases involved, timescales, and implications for galaxy chemical evolution.

Contribution

It provides a comprehensive review of metal enrichment processes in dwarf galaxies, highlighting the role of neutral and ionized gas phases and discussing metal ejection scenarios.

Findings

Neutral gas may be metal-deficient compared to ionized regions

Abundance determination from UV absorption lines has significant caveats

Metals may be ejected into the intergalactic medium

Abstract

The fate of metals after they are released in starburst episodes is still unclear. What phases of the interstellar medium are involved, in which timescales? Evidence has grown over the past few years that the neutral phase of blue compact dwarf (BCD) galaxies may be metal- deficient as compared to the ionized gas of their HII regions. These results have strong implications for our understanding of the chemical evolution of galaxies. We review here the main results and the main caveats in the abundance determination from far-UV absorption-lines. We also discuss possible scenarios concerning the journey of metals into the interstellar medium, or even their ejection from the galaxy into the intergalactic medium.