Early-type dwarf galaxies in clusters: a mixed bag with various origins?

TL;DR

This paper reviews the diverse origins of early-type dwarf galaxies in clusters, discussing various formation mechanisms and their implications for galaxy evolution, highlighting the complexity and multiple pathways involved.

Contribution

It provides an overview of the different subclasses of dE galaxies and explores the potential multiple formation channels contributing to their diversity.

Findings

Multiple dE subclasses with distinct properties identified

Different formation mechanisms likely contribute to dE diversity

The role of cosmological formation remains uncertain

Abstract

The formation of early-type dwarf (dE) galaxies, the most numerous objects in clusters, is believed to be closely connected to the physical processes that drive galaxy cluster evolution, like galaxy harassment and ram-pressure stripping. However, the actual significance of each mechanism for building the observed cluster dE population is yet unknown. Several distinct dE subclasses were identified, which show significant differences in their shape, stellar content, and distribution within the cluster. Does this diversity imply that dEs originate from various formation channels? Does "cosmological" formation play a role as well? I try to touch on these questions in this brief overview of dEs in galaxy clusters.