Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Millennium Arecibo 21-cm Absorption Line Survey. IV. Statistics of
  Magnetic Field, Column Density, and Turbulence   We discuss observations of the magnetic field, column density, and turbulence
in the Cold Neutral Medium (CNM). The observed quantities are only indirectly
related to the intrinsic astronomical ones. We relate the observed and
intrinsic quantities by relating their univariate and bivariate probability
distribution functions (pdfs). We find that observations of the line-of-sight
component of magnetic field do not constrain the pdf of the total field very
well, but do constrain the median value of the total field.
  In the CNM, we find a well-defined median magnetic field 6.0 +/-1.8
microGauss. The CNM magnetic field dominates thermal motions. Turbulence and
magnetism are in approximate equipartition. We find the probability
distribution of HI column density Nperp in the sheets closely follows Nperp^-1
over a range of two orders of magnitude, 0.026 < Nperp < 2.6 (times 10^20
cm^-2). The bivariate distributions are not well enough determined to constrain
structural models of CNM sheets.

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The categories of this paper are: hep-th
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: gr-qc
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The categories of this paper are: math
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The categories of this paper are: acc-phys
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The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
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The categories of this paper are: q-alg
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The categories of this paper are: bayes-an
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The categories of this paper are: eess
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The categories of this paper are: dg-ga
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The categories of this paper are: comp-gas
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-ph