Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Detection of water vapor in the terrestrial planet forming region of a
  transition disk   We report a detection of water vapor in the protoplanetary disk around DoAr
44 with the Texas Echelon Cross Echelle Spectrograph --- a visitor instrument
on the Gemini north telescope. The DoAr 44 disk consists of an optically thick
inner ring and outer disk, separated by a dust-cleared 36 AU gap, and has
therefore been termed "pre-transitional". To date, this is the only disk with a
large inner gap known to harbor detectable quantities of warm (T=450 K) water
vapor. In this work, we detect and spectrally resolve three mid-infrared pure
rotational emission lines of water vapor from this source, and use the shapes
of the emission lines to constrain the location of the water vapor. We find
that the emission originates near 0.3 AU --- the inner disk region. This
characteristic region coincides with that inferred for both optically thick and
thin thermal infrared dust emission, as well as rovibrational CO emission. The
presence of water in the dust-depleted region implies substantial columns of
hydrogen (>10^{22} cm-2) as the water vapor would otherwise be destroyed by
photodissociation. Combined with the dust modeling, this column implies a
gas/small-dust ratio in the optically thin dusty region of >1000. These results
demonstrate that DoAr 44 has maintained similar physical and chemical
conditions to classical protoplanetary disks in its terrestrial-planet forming
regions, in spite of having formed a large gap.

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The categories of this paper are: chao-dyn
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The categories of this paper are: patt-sol
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
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The categories of this paper are: quant-ph
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The categories of this paper are: econ
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The categories of this paper are: gr-qc
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The categories of this paper are: mtrl-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: plasm-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph