Morphological Transformations of Galaxies in the A901/02 Supercluster from STAGES

TL;DR

This study investigates how galaxy morphologies and star formation are affected by their environment in the Abell 901/902 supercluster, revealing the influence of local density and external interactions on galaxy evolution.

Contribution

It provides a detailed comparison of distorted and undistorted galaxies using multi-wavelength data, highlighting environmental effects on galaxy morphology and star formation.

Findings

Distorted galaxies are more common in dense regions.

Environmental factors influence galaxy morphology and star formation.

Morphology-density relation varies when considering bulge-to-disk ratio and gas content.

Abstract

We present a study of galaxies in the Abell 901/902 Supercluster at z~0.165, based on HST ACS F606W, COMBO-17, Spitzer 24um, XMM-Newton X-ray, and gravitational lensing maps, as part of the STAGES survey. We characterize galaxies with strong externally-triggered morphological distortions and normal relatively undisturbed galaxies, using visual classification and quantitative CAS parameters. We compare normal and distorted galaxies in terms of their frequency, distribution within the cluster, star formation properties, and relationship to dark matter (DM) or surface mass density, and intra-cluster medium (ICM) density. We revisit the morphology density relation, which postulates a higher fraction of early type galaxies in dense environments, by considering separately galaxies with a low bulge-to-disk (B/D) ratio and a low gas content as these two parameters may not be correlated in clusters. We report here on our preliminary analysis.