Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radio galaxies in the 2SLAQ Luminous Red Galaxy survey: II. The stellar
  populations of radio-loud and radio-quiet LRGs   We present an analysis of the optical spectra of a volume-limited sample of
375 radio galaxies at redshift 0.4<z<0.7 from the 2dF-SDSS Luminous Red Galaxy
and QSO (2SLAQ) redshift survey. We investigate the evolution of the stellar
populations and emission-line properties of these galaxies. By constructing
composite spectra and comparing with a matched sample of radio-quiet sources
from the same survey, we also investigate the effect on the galaxy of the
presence of an active nucleus.
  The composite spectra, binned by redshift and radio luminosity, all require
two components to describe them, which we interpret as an old and a younger
population. We found no evolution with redshift of the age of the younger
population in radio galaxies, nor were they different from the radio-quiet
comparison sample. Similarly, there is no correlation with radio power, with
the exception that the most powerful radio sources (P(1.4) > 10^26 W/Hz) have
younger stars and stronger emission lines than the less powerful sources. This
suggests that we have located the threshold in radio power where strong
emission lines "switch on", at radio powers of around 10^26 W/Hz. Except for
the very powerful radio galaxies, the presence of a currently-active radio AGN
does not appear to be correlated with any change in the observed stellar
population of a luminous red galaxy at z~0.5.

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The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
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The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
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The categories of this paper are: atom-ph
1
The categories of this paper are: cs
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The categories of this paper are: supr-con
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The categories of this paper are: dg-ga
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The categories of this paper are: nlin
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The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph