Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Comparing Mid-Infrared Globular Cluster Colors With Population Synthesis
  Models   Several population synthesis models now predict integrated colors of simple
stellar populations in the mid-infrared bands. To date, the models have not
been extensively tested in this wavelength range. In a comparison of the
predictions of several recent population synthesis models, the integrated
colors are found to cover approximately the same range but to disagree in
detail, for example on the effects of metallicity. To test against
observational data, globular clusters are used as the closest objects to
idealized groups of stars with a single age and single metallicity. Using
recent mass estimates, we have compiled a sample of massive, old globular
clusters in M31 which contain enough stars to guard against the stochastic
effects of small-number statistics, and measured their integrated colors in the
Spitzer/IRAC bands. Comparison of the cluster photometry in the IRAC bands with
the model predictions shows that the models reproduce the cluster colors
reasonably well, except for a small (not statistically significant) offset in
[4.5]-[5.8]. In this color, models without circumstellar dust emission predict
bluer values than are observed. Model predictions of colors formed from the V
band and the IRAC 3.6 and 4.5 micron bands are redder than the observed data at
high metallicities and we discuss several possible explanations. In agreement
with model predictions, V-[3.6] and V-[4.5] colors are found to have
metallicity sensitivity similar to or slightly better than V-Ks.

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The categories of this paper are: adap-org
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The categories of this paper are: gr-qc
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The categories of this paper are: nlin
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The categories of this paper are: econ
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The categories of this paper are: cond-mat
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The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-lat
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The categories of this paper are: q-alg
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The categories of this paper are: supr-con
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The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn