A&A 394, L15-L18 (2002)
A metallicity-flattening relation for dwarf elliptical galaxiesF. D. Barazza and B. Binggeli
Astronomisches Institut, Universität Basel, Venusstrasse 7, 4102 Binningen, Switzerland
(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 1994).
Key words: galaxies: general -- galaxies: fundamental parameters -- galaxies: elliptical -- galaxies: dwarf -- galaxies: evolution
Offprint request: F. D. Barazza, email@example.com
© ESO 2002