Chemical and stellar properties of early-type dwarf galaxies around the Milky Way

TL;DR

This paper reviews the chemical and stellar properties of early-type dwarf galaxies around the Milky Way, emphasizing their role in understanding galaxy evolution, star formation, and chemical enrichment histories through recent survey data.

Contribution

It provides a comprehensive summary of recent advances in understanding the stellar populations and chemical properties of early-type dwarf galaxies using large-scale survey data.

Findings

Diverse star-formation histories observed in nearby dwarfs.

Progress in identifying sites of heavy element production.

Early-type dwarfs serve as laboratories for studying galaxy evolution.

Abstract

Early-type dwarfs (ETDs) are the end points of the evolution of low-mass galaxies whose gas supply has been extinguished. The cessation of star-formation lays bare the ancient stellar populations. A wealth of information is stored in the colours, magnitudes, metallicities and abundances of resolved stars of the dwarf spheroidal and ultra-faint galaxies around the Milky Way, allowing their chemistry and stellar populations to be studied in great detail. Here, we summarize our current understanding, which has advanced rapidly over the last decade thanks to the flourishing of large-scale astrometric, photometric and spectroscopic surveys. We emphasise that the primeval stellar populations in the ETDs provide a unique laboratory to study the physical conditions on small scales at epochs beyond z=2. We highlight the observed diversity of star-formation and chemical enrichment histories in nearby dwarfs. These data can not yet be fully deciphered to reveal the key processes in the dwarf evolution but the first successful attempts have been made to pin down the sites of heavy element production.