Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radio-Selected Quasars in the Sloan Digital Sky Survey   We have conducted a pilot survey for z>3.5 quasars by combining the FIRST
radio survey with the SDSS. While SDSS already targets FIRST sources for
spectroscopy as quasar candidates, our survey includes fainter quasars and
greatly improves the discovery rate by using strict astrometric criteria for
matching the radio and optical positions. Our method allows for selection of
high-redshift quasars with less color bias than with optical selection, as
using radio selection essentially eliminates stellar contamination. We report
the results of spectroscopy for 45 candidates, including 29 quasars in the
range 0.37 < z < 5.2, with 7 having redshifts z>3.5. We compare quasars
selected using radio and optical criteria, and find that radio-selected quasars
have a much higher fraction of moderately-reddened objects. We derive a
radio-loud quasar luminosity function at 3.5<z<4.0, and find that it is in good
agreement with expectations from prior SDSS results.

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The categories of this paper are: hep-th
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The categories of this paper are: funct-an
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The categories of this paper are: hep-lat
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The categories of this paper are: comp-gas
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The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: plasm-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: alg-geom