Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dust, Ice and Gas in Time (DIGIT) Herschel program first results: A full
  PACS-SED scan of the gas line emission in protostar DK Cha   DK Cha is an intermediate-mass star in transition from an embedded
configuration to a star plus disk stage. We aim to study the composition and
energetics of the circumstellar material during this pivotal stage. Using the
Range Scan mode of PACS on the Herschel Space Observatory, we obtained a
spectrum of DK Cha from 55 to 210 micron as part of the DIGIT Key Program.
Almost 50 molecular and atomic lines were detected, many more than the 7 lines
detected in ISO-LWS. Nearly the entire ladder of CO from J=14-13 to 38-37
(E_u/k = 4080 K), water from levels as excited as E_u/k = 843 K, and OH lines
up to E_u/k = 290 K were detected. The continuum emission in our PACS SED scan
matches the flux expected from a model consisting of a star, a surrounding disk
of 0.03 Solar mass, and an envelope of a similar mass, supporting the
suggestion that the object is emerging from its main accretion stage.
Molecular, atomic, and ionic emission lines in the far-infrared reveal the
outflow's influence on the envelope. The inferred hot gas can be photon-heated,
but some emission could be due to C-shocks in the walls of the outflow cavity.

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The categories of this paper are: physics
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The categories of this paper are: plasm-ph
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The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
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The categories of this paper are: gr-qc
1
The categories of this paper are: cs
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The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
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The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: nlin