# Two channels for the formation of compact dwarf galaxies in clusters of galaxies

## TL;DR

This paper identifies two formation channels for compact dwarf galaxies in clusters: tidal stripping of external galaxies and in-situ formation within the cluster, supported by simulation data.

## Contribution

It reveals the existence of two distinct formation pathways for compact dwarf galaxies in clusters, with detailed analysis from the Illustris simulation.

## Key findings

- 19 compact dwarf galaxies identified in 14 clusters
- 30% of these dwarfs originate externally, 70% form in-situ
- Results align with observational data

## Abstract

We have identified two channels for the formation of compact dwarf galaxies in the Illustris simulation by reconstructing mass and distance histories of candidates located in the vicinity of the simulation's most massive cluster galaxies. One channel is tidal stripping of Milky Way mass galaxies that form outside of clusters and eventually sink into them, spiraling in toward central massive objects. Second channel of formation is an in-situ formation (in reference to the parent cluster) of dwarf mass galaxies, with negligible evolution and limited change in stellar mass. We find 19 compact dwarf galaxies at the centers of 14 clusters, consistent with observations. 30% of them have external origin while 70% are formed in-situ.