Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Spectral Correlation Function of Molecular Clouds: A Statistical
  Test for Theoretical Models   We compute the spectral correlation function (SCF) of 13CO J=1--0 maps of
molecular cloud complexes. The SCF is a power law over approximately an order
of magnitude in spatial separation in every map. The power law slope of the
SCF, alpha, its normalization, S_0(1pc), and the spectral line width averaged
over the whole map, sigma_v, are computed for all the observational maps. The
values of alpha, S_0(1pc) and sigma_v are combined to obtain empirical
correlations to be used as tests for theoretical models of molecular clouds.
Synthetic spectral maps are computed from different theoretical models,
including solutions of the magneto-hydrodynamic (MHD) equations with different
values of the rms Mach number of the flow and stochastic models with different
power spectra of the velocity field. In order to compute the radiative transfer
from the MHD models it is necessary to assign the models a physical scale and a
physical density. When these assignments are made according to Larson type
relations the best fit to the observational correlations is obtained.
Unphysical stochastic models are instead ruled out by the empirical
correlations. MHD models with equipartition of magnetic and kinetic energy of
turbulence do not reproduce the observational data when their average magnetic
field is oriented approximately parallel to the line of sight.

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The categories of this paper are: chem-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-ex
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The categories of this paper are: physics
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-lat
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The categories of this paper are: atom-ph
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The categories of this paper are: funct-an
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The categories of this paper are: nlin
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The categories of this paper are: q-fin