Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ages and Metallicities of Fornax Dwarf Ellipticals   Narrow band photometry is presented on 27 dwarf ellipticals in the Fornax
cluster. Calibrated with Galactic globular cluster data and spectrophotometric
population models, the colors indicated that dwarf ellipticals have a mean
[Fe/H] of -1.00+/-0.28 ranging from -1.6 to -0.4. The mean age of dwarf
ellipticals, also determined photometrically, is estimated at 10+/-1 Gyrs
compared to 13 Gyrs for bright Fornax ellipticals. Comparison of our
metallicity color and Mg_2 indices demonstrates that the [Mg/Fe] ratio is lower
in dwarf ellipticals than their more massive cousins, which is consistent with
a longer duration of initial star formation to explain their younger ages.
There is a increase in dwarf metallicity with distance from the Fornax cluster
center where core galaxies are, on average, 0.5 dex more metal-poor than halo
dwarfs. In addition, we find the halo dwarfs are younger in mean age compared
to core dwarfs. One possible explanation is that the intracluster medium ram
pressure strips the gas from dwarf ellipticals halting star formation (old age)
and stopping enrichment (low metallicity) as they enter the core.

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The categories of this paper are: chao-dyn
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The categories of this paper are: q-alg
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The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-th
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The categories of this paper are: comp-gas
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The categories of this paper are: cond-mat
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The categories of this paper are: funct-an
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The categories of this paper are: atom-ph
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The categories of this paper are: stat
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The categories of this paper are: nlin
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The categories of this paper are: plasm-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
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The categories of this paper are: bayes-an