Letter to the Editor
A metallicity-flattening relation for dwarf elliptical galaxies
Astronomisches Institut, Universität Basel, Venusstrasse 7, 4102 Binningen, Switzerland
Corresponding author: F. D. Barazza, firstname.lastname@example.org
Accepted: 5 September 2002
It is shown that bright cluster dwarf ellipticals follow a relation between metallicity and apparent flattening. Rounder dwarfs tend to be more metal-rich. The evidence is based on colour as well as spectroscopic line-strength data from the literature. The large scatter of dEs around the mean metallicity-luminosity relation, usually ascribed to large observational errors, turns out to be an ellipticity effect. In the magnitude range the metallicity of dEs depends more strongly on ellipticity than luminosity. A possible explanation is that galaxies with masses around suffered a partial blowout of metal-enriched gas along their minor axis, rendering ellipticity a critical parameter for metallicity (De Young & Heckman [CITE]).
Key words: galaxies: general / galaxies: fundamental parameters / galaxies: elliptical / galaxies: dwarf / galaxies: evolution
© ESO, 2002