Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Near-Infrared Multiplicity Survey of Class I/Flat-Spectrum Systems in
  Six Nearby Molecular Clouds   We present new near-IR observations of 76 Class I/flat-spectrum objects in
the nearby (d < 320 pc) Perseus, Taurus, Chamaeleon I and II, rho Ophiuchi, and
Serpens dark clouds. These observations are part of a larger systematic
infrared multiplicity survey of self-embedded objects in the nearest dark
clouds. When combined with the results of our previously published
near-infrared multiplicity survey, we find a restricted companion star fraction
of 14/79 (18% +/- 4%) of the sources surveyed to be binary or higher order
multiple systems over a separation range of ~300 - 2000 AU with a magnitude
difference $\Delta$ K <= 4, and with no correction for background contamination
or completeness. This is consistent with the fraction of binary/multiple
systems found among older pre-main-sequence T Tauri stars in each of the
Taurus, rho Ophiuchi, and Chamaeleon star-forming regions over a similar
separation range, as well as the combined companion star fraction for these
regions. However, the companion star fraction for solar-type, and lower mass M
dwarf, main-sequence stars in the solar neighborhood in this separation range
(11% +/- 3%) is approximately one-half that of our sample. Together with
multiplicity statistics derived for previously published samples of Class 0 and
Class I sources, our study suggests that a significant number of
binary/multiple objects may remain to be discovered at smaller separations
among our Class I/flat-spectrum sample and/or most of the evolution of
binary/multiple systems occurs during the Class 0 phase of early stellar
evolution.

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The categories of this paper are: quant-ph
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The categories of this paper are: funct-an
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The categories of this paper are: adap-org
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The categories of this paper are: cs
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The categories of this paper are: math
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The categories of this paper are: physics
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The categories of this paper are: cond-mat
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The categories of this paper are: q-alg
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The categories of this paper are: hep-ph
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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: q-bio
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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: plasm-ph
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The categories of this paper are: chem-ph