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A metallicity-flattening relation for dwarf elliptical galaxies

Fabio D. Barazza·Bruno Binggeli
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Abstract

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 $-14 \ga M_B \ga -18$ the metallicity of dEs depends more strongly on ellipticity than luminosity. A possible explanation is that galaxies with masses around $10^{9}$ $M_{\odot}$ suffered a partial blowout of metal-enriched gas along their minor axis, rendering ellipticity a critical parameter for metallicity (De Young & Heckman 1994).

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Fabio D. Barazza, Bruno Binggeli. 2002-09-09. A metallicity-flattening relation for dwarf elliptical galaxies. https://doi.org/10.1051/0004-6361%3A20021294

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