Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The SDSS-III BOSS quasar lens survey: discovery of thirteen
  gravitationally lensed quasars   We report the discovery of 13 confirmed two-image quasar lenses from a
systematic search for gravitationally lensed quasars in the SDSS-III Baryon
Oscillation Spectroscopic Survey (BOSS). We adopted a methodology similar to
that used in the SDSS Quasar Lens Search (SQLS). In addition to the confirmed
lenses, we report 11 quasar pairs with small angular separations ($\lesssim$2")
confirmed from our spectroscopy, which are either projected pairs, physical
binaries, or possibly quasar lens systems whose lens galaxies have not yet been
detected. The newly discovered quasar lens system, SDSS J1452+4224 at
zs$\approx$4.8 is one of the highest redshift multiply imaged quasars found to
date. Furthermore, we have over 50 good lens candidates yet to be followed up.
Owing to the heterogeneous selection of BOSS quasars, the lens sample presented
here does not have a well-defined selection function.

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The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: mtrl-th
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The categories of this paper are: supr-con
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The categories of this paper are: stat
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
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The categories of this paper are: cmp-lg