Elliptical galaxies follow a well-known luminosity – metallicity (L − Z)
relation, in the sense that more luminous ellipticals are observed to be
more metal-rich than less luminous systems. Obviously this is a mass – Z
relation, and its interpretation is that less massive galaxies had more
significant outflows of metal-enriched gas at an early evolutionary stage.
The apparent ellipticity (ϵ) had already been invoked to explain
the large scatter in the L − Z relation, but Barazza & Binggeli
(2002) observed that the relation between Z and ϵ in cluster
dwarf elliptical galaxies (dEs) could even be stronger than the relation
with mass. The idea is that outflow of metal-enriched gas preferentially
occurs along the minor axis, making ϵ a critical parameter for Z in
dwarfs.
Here, we test this hypothesis using high-resolution N-body/SPH simulations
including chemical feedback of dEs with different flattenings.