Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The rotating molecular core and precessing outflow of the young stellar
  object Barnard 1c   We investigate the structure of the core surrounding the recently identified
deeply embedded young stellar object Barnard 1c which has an unusual
polarization pattern as traced in submillimeter dust emission. Barnard 1c lies
within the Perseus molecular cloud at a distance of 250 pc. It is a deeply
embedded core of 2.4 solar masses (Kirk et al.) and a luminosity of 4 +/- 2
solar luminosities. Observations of CO, 13CO, C18O, HCO+ and N2H+ were obtained
with the BIMA array, together with the continuum at 3.3 mm and 2.7 mm.
Single-dish measurements of N2H+ and HCO+ with FCRAO reveal the larger scale
emission in these lines, The CO and HCO+ emission traces the outflow, which
coincides in detail with the S-shaped jet recently found in Spitzer IRAC
imaging. The N2H+ emission, which anticorrelates spatially with the C18O
emission, originates from a rotating envelope with effective radius ~ 2400 AU
and mass 2.1 - 2.9 solar masses. N2H+ emission is absent from a 600 AU diameter
region around the young star. The remaining N2H+ emission may lie in a coherent
torus of dense material. With its outflow and rotating envelope, B1c closely
resembles the previously studied object L483-mm, and we conclude that it is a
protostar in an early stage of evolution. We hypothesize that heating by the
outflow and star has desorbed CO from grains which has destroyed N2H+ in the
inner region and surmise that the presence of grains without ice mantles in
this warm inner region can explain the unusual polarization signature from B1c.

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The categories of this paper are: solv-int
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The categories of this paper are: cond-mat
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph
3
The categories of this paper are: physics
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The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: chem-ph
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The categories of this paper are: cs
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The categories of this paper are: nlin
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The categories of this paper are: comp-gas
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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-th