Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Evolution of the Field and Cluster Morphology-Density Relation for
  Mass-Selected Samples of Galaxies   The Sloan Digital Sky Survey (SDSS) and photometric/spectroscopic surveys in
the GOODS-South field (the Chandra Deep Field-South, CDFS) are used to
construct volume-limited, stellar mass-selected samples of galaxies at
redshifts 0<z<1. The CDFS sample at 0.6<z<1.0 contains 207 galaxies complete
down to M=4x10^10 Msol (for a ``diet'' Salpeter IMF), corresponding to a
luminosity limit for red galaxies of M_B=-20.1. The SDSS sample at
0.020<z<0.045 contains 2003 galaxies down to the same mass limit, which
corresponds to M_B=-19.3 for red galaxies. Morphologies are determined with an
automated method, using the Sersic parameter n and a measure of the residual
from the model fits, called ``bumpiness'', to distinguish different
morphologies. These classifications are verified with visual classifications.
In agreement with previous studies, 65-70% of the galaxies are located on the
red sequence, both at z~0.03 and at z~0.8. Similarly, 65-70% of the galaxies
have n>2.5. The fraction of E+S0 galaxies is 43+/-3%$ at z~0.03 and 48+/-7% at
z~0.8, i.e., it has not changed significantly since z~0.8. When combined with
recent results for cluster galaxies in the same redshift range, we find that
the morphology-density relation for galaxies more massive than 0.5M* has
remained constant since at least z~0.8. This implies that galaxies evolve in
mass, morphology and density such that the morphology-density relation does not
change. In particular, the decline of star formation activity and the
accompanying increase in the stellar mass density of red galaxies since z~1
must happen without large changes in the early-type galaxy fraction in a given
environment.

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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-lat
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: acc-phys
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The categories of this paper are: comp-gas
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The categories of this paper are: physics
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The categories of this paper are: q-bio
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The categories of this paper are: eess
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The categories of this paper are: patt-sol
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The categories of this paper are: q-alg
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The categories of this paper are: atom-ph
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The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg