Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Evidence for Decay of Turbulence by MHD Shocks in Molecular Clouds via
  CO Emission   We utilize observations of sub-millimeter rotational transitions of CO from a
Herschel Cycle 2 open time program ("COPS", PI: J. Green) to identify
previously predicted turbulent dissipation by magnetohydrodynamic (MHD) shocks
in molecular clouds. We find evidence of the shocks expected for dissipation of
MHD turbulence in material not associated with any protostar. Two models fit
about equally well: model 1 has a density of 10$^{3}$ cm$^{-3}$, a shock
velocity of 3 km s$^{-1}$, and a magnetic field strength of 4 ${\mu}$G; model 2
has a density of 10$^{3.5}$ cm$^{-3}$, a shock velocity of $2$ km s$^{-1}$, and
a magnetic field strength of 8 $\mu$G. Timescales for decay of turbulence in
this region are comparable to crossing times. Transitions of CO up to $J$ of 8,
observed close to active sites of star formation, but not within outflows, can
trace turbulent dissipation of shocks stirred by formation processes. Although
the transitions are difficult to detect at individual positions, our
Herschel-SPIRE survey of protostars provides a grid of spatially-distributed
spectra within molecular clouds. We averaged all spatial positions away from
known outflows near seven protostars. We find significant agreement with
predictions of models of turbulent dissipation in slightly denser (10$^{3.5}$
cm$^{-3}$) material with a stronger magnetic field (24 $\mu$G) than in the
general molecular cloud.

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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
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The categories of this paper are: mtrl-th
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The categories of this paper are: comp-gas
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The categories of this paper are: cmp-lg
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The categories of this paper are: math
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The categories of this paper are: hep-th
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The categories of this paper are: econ
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The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: eess
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The categories of this paper are: q-bio
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The categories of this paper are: atom-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: funct-an