Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Deep Proper Motion Catalog Within The Sloan Digital Sky Survey
  Footprint   A new proper motion catalog is presented, combining the Sloan Digital Sky
Survey (SDSS) with second epoch observations in the r band within a portion of
the SDSS imaging footprint. The new observations were obtained with the 90prime
camera on the Steward Observatory Bok 90 inch telescope, and the Array Camera
on the U.S. Naval Observatory, Flagstaff Station, 1.3 meter telescope. The
catalog covers 1098 square degrees to r = 22.0, an additional 1521 square
degrees to r = 20.9, plus a further 488 square degrees of lesser quality data.
Statistical errors in the proper motions range from 5 mas/year at the bright
end to 15 mas/year at the faint end, for a typical epoch difference of 6 years.
Systematic errors are estimated to be roughly 1 mas/year for the Array Camera
data, and as much as 2 - 4 mas/year for the 90prime data (though typically
less). The catalog also includes a second epoch of r band photometry.

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The categories of this paper are: econ
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The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
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The categories of this paper are: math
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The categories of this paper are: q-fin
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The categories of this paper are: stat
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-th
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The categories of this paper are: adap-org
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-lat
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-alg
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The categories of this paper are: physics
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The categories of this paper are: cs