Groups of dwarf galaxies in the Local supercluster

TL;DR

This study identifies and characterizes groups of dwarf galaxies in the Local supercluster, revealing their properties and potential dark matter content, and suggesting they are in pre-merging stages.

Contribution

First systematic identification and analysis of dwarf galaxy groups in the Local supercluster using multiple databases and imaging data.

Findings

Dwarf galaxy groups have sizes of a few tens of kpc.

Line-of-sight velocity dispersion is about 18 km/s.

These groups may contain significant dark matter and are likely in pre-merging stages.

Abstract

We present a project on study of groups composed of dwarf galaxies only. We selected such structures using HyperLEDA and NED databases with visual inspection on SDSS images and on digital copy of POSS. The groups are characterized by size of few tens of kpc and line-of-sight velocity dispersion about 18 km/s. Our groups similar to associations of nearby dwarfs from Tully et al. (2006). This specific population of multiple dwarf galaxies such as IZw18 may contain significant amount of dark matter. It is very likely that we see them at the stage just before merging of its components.