Growth of Diffuse Intragroup Light in Simulated Galaxy Groups

TL;DR

This study uses simulations to explore how diffuse intragroup light forms and evolves in galaxy groups, revealing correlations with group properties and its potential as a gravitational potential tracer.

Contribution

It provides new insights into the formation timing, growth mechanisms, and the relationship between IGL and group dynamics in galaxy groups during pre-virialization.

Findings

IGL begins forming around the turnaround epoch.

Lower velocity dispersion correlates with higher IGL fraction.

IGL density profiles resemble total mass profiles.

Abstract

The diffuse intragroup light (IGL) is a pervasive feature of galaxy groups consisting of an extended low-surface-brightness component that permeates the intergalactic medium of these galaxy associations. It is primarily formed by stars separated from their host galaxies and now drift freely, unbound to any particular galaxy. We used controlled numerical simulations to investigate the formation and evolution of IGL in galaxy groups during the pre-virialization phase. Our study reveals that the emergence of this diffuse luminous component typically begins to form in significant amounts around the turnaround epoch, increasing steadily thereafter. We analyzed the correlation between the mass and fraction of IGL and other group properties. We found a sublinear relationship between the IGL mass and the brightest group galaxy, suggesting intertwined formation histories but with potentially differing growth rates and distinct driving mechanisms. Additionally, we observed a negative correlation between the IGL fraction and the group's velocity dispersion, indicating that a lower velocity dispersion may enhance IGL formation through increased gravitational interaction effectiveness. Furthermore, our comparative analysis of the density profiles of IGL and total system mass revealed significant similarities, suggesting that the intragroup light serves as a reliable tracer of the gravitational potential of host groups, even when these galaxy aggregations are far from dynamic equilibrium.