Using deep images and simulations to trace collisional debris around massive galaxies

TL;DR

This study uses deep imaging and simulations to identify and analyze collisional debris around massive galaxies, enabling reconstruction of their merger histories.

Contribution

It provides a systematic census of fine structures around galaxies and estimates their visibility and lifetime using simulations, advancing understanding of galaxy assembly.

Findings

Identification of various debris types such as streams, tails, plumes, and shells.

Estimation of the visibility and lifetime of these structures.

Preliminary statistical analysis of 360 galaxies' merger histories.

Abstract

Deep imaging programs, such as MATLAS which has just been completed at the CFHT, allows us to study with their diffuse light the outer stellar populations around large number of galaxies. We have carried out a systematic census of their fine structures, i.e. the collisional debris from past mergers. We have identified among them stellar streams from minor mergers, tidal tails from gas-rich major mergers, plumes from gas-poor major mergers, and shells from intermediate mass mergers. Having estimated the visibility and life time of each of these structures with numerical simulations, we can reconstruct the past mass assembly of the host galaxy. Preliminary statistical results based on a sample of 360 massive nearby galaxies are presented.