Searching for tidal tails - investigating galaxy harassment

TL;DR

This study develops a sensitive method to detect tidal streams around dwarf elliptical galaxies but finds no evidence of such features in the Virgo cluster, challenging galaxy harassment as a formation mechanism.

Contribution

The paper introduces a new analysis technique for detecting low surface brightness tidal features and applies it to Virgo cluster dwarfs, providing observational constraints.

Findings

No tidal streams detected around the 46 Virgo dwarf ellipticals

Results challenge galaxy harassment as the main formation process

Method sensitive to features down to 29 B mag/arcsec^2

Abstract

Galaxy harassment has been proposed as a physical process that morphologically transforms low surface density disc galaxies into dwarf elliptical galaxies in clusters. It has been used to link the observed very different morphology of distant cluster galaxies (relatively more blue galaxies with 'disturbed' morphologies) with the relatively large numbers of dwarf elliptical galaxies found in nearby clusters. One prediction of the harassment model is that the remnant galaxies should lie on low surface brightness tidal streams or arcs. We demonstrate in this paper that we have an analysis method that is sensitive to the detection of arcs down to a surface brightness of 29 B mag/arcsec^2 and then use this method to search for arcs around 46 Virgo cluster dwarf elliptical galaxies. We find no evidence for tidal streams or arcs and consequently no evidence for galaxy harassment as a viable explanation for the relatively large numbers of dwarf galaxies found in the Virgo cluster.