Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic Fields and the Polarization of Astrophysical Maser Radiation: A
  Review   Basic aspects of the relationship between the magnetic field and polarized
maser radiation are described with the emphasis on interpreting the observed
spectra. Special attention is given to three issues--the limitations on the
applicability of the classic solutions of Goldreich, Keeley & Kwan (1973),
inferring the strength of the magnetic field from the circular polarization
when the Zeeman splitting is much less than the spectral linebreadth
(especially for SiO masers), and the significance of the absence of components
of the Zeeman triplet in the spectra of OH masers in regions of star formation.

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The categories of this paper are: quant-ph
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
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The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
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The categories of this paper are: q-alg
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The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
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The categories of this paper are: nucl-th
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The categories of this paper are: eess
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The categories of this paper are: chem-ph
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The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
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The categories of this paper are: comp-gas