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, barazza@astro.unibas.ch
Received:
2
September
2002
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