The Environmental Dependence of the Incidence of Galactic Tidal Features

TL;DR

This study investigates how the environment within galaxy clusters influences the occurrence of tidal features in early-type galaxies, revealing a decrease in such features closer to the cluster center and implications for galaxy evolution.

Contribution

It provides the first large-scale analysis of tidal features in cluster galaxies, demonstrating environmental dependence and offering insights into galaxy-halo interactions and cluster evolution.

Findings

Approximately 3% of galaxies show detectable tidal features.

Tidal features are less common within 0.5R_200 of cluster centers.

No clear link between local density and tidal feature incidence.

Abstract

In a sample of 54 galaxy clusters (0.04<z<0.15) containing 3551 early-type galaxies suitable for study, we identify those with tidal features both interactively and automatically. We find that ~3% have tidal features that can be detected with data that reaches a 3-sigma sensitivity limit of 26.5 mag arcsec^-2. Regardless of the method used to classify tidal features, or the fidelity imposed on such classifications, we find a deficit of tidally disturbed galaxies with decreasing clustercentric radius that is most pronounced inside of ~0.5R_200. We cannot distinguish whether the trend arises from an increasing likelihood of recent mergers with increasing clustercentric radius or a decrease in the lifetime of tidal features with decreasing clustercentric radius. We find no evidence for a relationship between local density and the incidence of tidal features, but our local density measure has large uncertainties. We find interesting behavior in the rate of tidal features among cluster early-types as a function of clustercentric radius and expect such results to provide constraints on the effect of the cluster environment on the structure of galaxy halos, the build-up of the red sequence of galaxies, and the origin of the intracluster stellar population.