The Interstellar Medium of Dwarf Galaxies

TL;DR

This review explores the physical and chemical properties of the interstellar medium in dwarf galaxies, highlighting their unique features, potential active nuclei, and cosmological significance related to early universe conditions.

Contribution

It provides a comprehensive overview of the interstellar medium in dwarf galaxies, including gas, dust, and active nuclei, and discusses their cosmological implications.

Findings

Dwarf galaxies have distinct interstellar medium properties compared to larger galaxies.

Presence of active nuclei in some dwarf galaxies suggests complex central activity.

Green Pea galaxies resemble early universe proto-galactic sources.

Abstract

Dwarf galaxies are by far the most numerous galaxies in the Universe, showing properties that are quite different from those of their larger and more luminous cousins. This review focuses on the physical and chemical properties of the interstellar medium of those dwarfs that are known to host significant amounts of gas and dust. The neutral and ionized gas components and the impact of the dust will be discussed, as well as first indications for the existence of active nuclei in these sources. Cosmological implications are also addressed, considering the primordial helium abundance and the similarity of local Green Pea galaxies with young, sometimes proto-galactic sources in the early Universe.