Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Broadband Optical Properties of Massive Galaxies: the Dispersion Around
  the Field Galaxy Color-Magnitude Relation Out to z~0.4   Using a sample of nearly 20,000 massive early-type galaxies selected from the
Sloan Digital Sky Survey, we study the color-magnitude relation for the most
luminous (L > 2.2 L^{*}) field galaxies in the redshift range 0.1<z<0.4 in
several colors. The intrinsic dispersion in galaxy colors is quite small in all
colors studied, but the 40 milli-mag scatter in the bluest colors is a factor
of two larger than the 20 milli-mag measured in the reddest bands. While each
of three simple models constructed for the star formation history in these
systems can satisfy the constraints placed by our measurements, none of them
produce color distributions matching those observed. Subdividing by
environment, we find the dispersion for galaxies in clusters to be about 11%
smaller than that of more isolated systems. Finally, having resolved the red
sequence, we study the color dependence of the composite spectra. Bluer
galaxies on the red sequence are found to have more young stars than red
galaxies; the extent of this spectral difference is marginally better described
by passive evolution of an old stellar population than by a model consisting of
a recent trace injection of young stars.

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The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: math-ph
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The categories of this paper are: chem-ph
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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: ao-sci
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The categories of this paper are: q-fin
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The categories of this paper are: dg-ga
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The categories of this paper are: econ
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The categories of this paper are: eess
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The categories of this paper are: physics
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The categories of this paper are: hep-lat
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The categories of this paper are: adap-org
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The categories of this paper are: math
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The categories of this paper are: alg-geom