Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Hawaii Infrared Parallax Program. IV. A Comprehensive Parallax
  Survey of L0-T8 dwarfs with UKIRT   We present parallaxes, proper motions, and $J$-band photometry for 348 L and
T dwarfs measured using the wide-field near-infrared camera WFCAM on the United
Kingdom Infrared Telescope. This is the largest single batch of infrared
parallaxes for brown dwarfs to date. Our parallaxes have a median uncertainty
of 3.5 mas, similar to most previous ground-based infrared parallax surveys.
Our target list was designed to complete a volume-limited parallax sample of
L0-T8 dwarfs out to 25 pc spanning declinations $-30^\circ$ to $+60^\circ$ (68%
of the sky). We report the first parallaxes for 165 objects, and we improve on
previous measurements for another 53 objects. Our targets include 104 objects
(mostly early-L dwarfs) having $Gaia$ DR2 parallax measurements, with which our
parallaxes are consistent. We include an extensive comparison of previous
literature parallaxes for L and T dwarfs with both our results and $Gaia$ DR2
measurements, identifying systematic offsets for some previous surveys. Our
parallaxes confirm that 14 objects previously identified as wide common proper
motion companions to main-sequence stars have distances consistent with
companionship. We also report new $J_\mathrm{MKO}$ photometry for our targets,
including the first measurements for 193 of our targets and improvements over
previously published $J_\mathrm{MKO}$ photometry for another 60 targets.
Altogether, our parallaxes will enable the first population studies using a
volume-limited sample spanning spectral types L0-T8 defined entirely by
parallaxes.

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The categories of this paper are: nucl-th
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The categories of this paper are: supr-con
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The categories of this paper are: bayes-an
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The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: mtrl-th
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The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: stat
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The categories of this paper are: comp-gas
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The categories of this paper are: acc-phys
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn