# HI in Virgo's "Red and Dead" Dwarf Ellipticals - A Tidal Tail and Central Star Formation

## TL;DR

This study examines three Virgo dwarf elliptical galaxies with significant HI reservoirs, revealing tidal interactions and central star formation, challenging the view of these galaxies as completely 'red and dead'.

## Contribution

First detailed multi-wavelength analysis of HI content and morphology in Virgo dwarf ellipticals showing signs of tidal interactions and ongoing star formation.

## Key findings

- VCC 190 has an HI tidal tail from a recent encounter.
- VCC 611 shows blue star-forming features.
- The galaxies' gas is unlikely to be recently accreted.

## Abstract

We investigate a sample of 3 dwarf elliptical galaxies in the Virgo Cluster which have significant reservoirs of HI. We present deep optical imaging (from CFHT and KPNO), HI spectra (Arecibo) and resolved HI imaging (VLA) of this sample. These observations confirm their HI content and optical morphologies, and indicate that the gas is unlikely to be recently accreted. The sample has more in common with dwarf transitionals, although dwarf transitionals are generally lower in stellar mass and gas fraction. VCC 190 has an HI tidal tail from a recent encounter with the massive spiral galaxy NGC 4224. In VCC 611, blue star-forming features are observed which were unseen by shallower SDSS imaging.