Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Color-magnitude relations of late-type galaxies   We use a large sample of galaxies drawn from the Sloan Digital Sky Survey
(SDSS) and Two Micro All Sky Survey (2MASS) to present Color-Magnitude
Relations (CMRs) for late-type galaxies in both optical and optical-infrared
bands. A sample from SDSS Data Release 4 (DR4) is selected to investigate the
optical properties. Optical-infrared colors are estimated from a position
matched sample of DR4 and 2MASS, in which the photometric aperture mismatch
between these two surveys is carefully corrected. It is shown that, after
correcting the dust attenuation, the optical colors for faint galaxies (i.e.
$M_r > -21$) have very weak correlation with the luminosity, while the optical
colors for bright galaxies (i.e. $M_r < -21$) are redder for more luminous
galaxies. All (optical, optical-infrared and infrared) colors show similar but
stronger correlations with stellar mass than with absolute magnitude. The
optical colors correlate more strongly with stellar mass surface density than
with stellar mass, while optical-infrared and infrared colors show stronger
correlations with stellar mass. By comparing the observed colors of our sample
galaxies with the colors predicted by stellar population synthesis model, we
find that massive late-type galaxies have older and higher metallicity stellar
population than less massive galaxies. This suggests that CMRs for late-type
galaxies are trends defined by the combination of stellar mean age and
metallicity. Moreover, our results suggest that the stellar mean metallicity of
late-type galaxy is mainly determined by its stellar mass, while the star
formation history is mainly regulated by the stellar mass surface density.

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The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: quant-ph
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: stat
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The categories of this paper are: cs
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The categories of this paper are: q-fin
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
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The categories of this paper are: plasm-ph
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The categories of this paper are: solv-int
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The categories of this paper are: chem-ph
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The categories of this paper are: math-ph