Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A metallicity-flattening relation for dwarf elliptical galaxies   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).

10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
18
The categories of this paper are: econ
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga