Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Distribution, Excitation and Formation of Cometary Molecules:
  Methanol, Methyl Cyanide and Ethylene Glycol   We present an interferometric and single dish study of small organic species
toward Comets C/1995 O1 (Hale-Bopp) and C/2002 T7 (LINEAR) using the BIMA
interferometer at 3 mm and the ARO 12m telescope at 2 mm. For Comet Hale-Bopp,
both the single-dish and interferometer observations of CH3OH indicate an
excitation temperature of 105+/-5 K and an average production rate ratio
Q(CH3OH)/Q(H2O)~1.3% at ~1 AU. Additionally, the aperture synthesis
observations of CH3OH suggest a distribution well described by a spherical
outflow and no evidence of significant extended emission. Single-dish
observations of CH3CN in Comet Hale-Bopp indicate an excitation temperature of
200+/-10 K and a production rate ratio of Q(CH3CN)/Q(H2O)~0.017% at ~1 AU. The
non-detection of a previously claimed transition of cometary (CH2OH)2 toward
Comet Hale-Bopp with the 12m telescope indicates a compact distribution of
emission, D<9'' (<8500 km). For the single-dish observations of Comet T7
LINEAR, we find an excitation temperature of CH3OH of 35+/-5 K and a CH3OH
production rate ratio of Q(CH3OH)/Q(H2O)~1.5% at ~0.3 AU. Our data support
current chemical models that CH3OH, CH3CN and (CH2OH)2 are parent nuclear
species distributed into the coma via direct sublimation off cometary ices from
the nucleus with no evidence of significant production in the outer coma.

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The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
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The categories of this paper are: patt-sol
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The categories of this paper are: stat
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The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
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The categories of this paper are: plasm-ph
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The categories of this paper are: funct-an
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The categories of this paper are: chem-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: q-fin
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The categories of this paper are: q-alg
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The categories of this paper are: comp-gas
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ex
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The categories of this paper are: math