N-Body Simulations of Small Galaxy Groups

TL;DR

This paper presents N-body simulations that successfully model small galaxy groups, reproducing observed properties and demonstrating their longevity without overmerging, challenging previous expectations.

Contribution

The study introduces detailed N-body simulations that accurately replicate small galaxy group dynamics and longevity, providing new insights into their evolution.

Findings

Small galaxy groups are well modeled by simulations.

Hickson's compact groups can be explained by collapsing groups.

No overmerging problem is observed in the simulations.

Abstract

A series of N-body simulations aimed to study the dynamics of small groups of galaxies are presented. The properties of small galaxy groups are very well reproduced, and those of Hickson's compact groups are well reproduced by the most advanced stage of collapsing groups. We find no overmerging problem in our simulations. An important fraction of groups (~40%) initially in virial equilibrium can last for ~10 Gyr without complete merging. These results provide an alternative solution to the overmerging expected in Hicksons's compact groups.