Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Two New Low Redshift 21cm Absorbers   As part of a larger program to identify low redshift radio analogues of the
damped Lyman-alpha (DLA) absorbers seen in the spectra of high redshift
quasars, Westerbork Synthesis Radio Telescope (WSRT) observations have
discovered two new HI 21cm absorption lines at z=0.394 and z=0.437 in the
spectra of the radio sources B 0248+430 and B 1243-072 respectively. These
sightlines and redshifts were selected for study on the basis of the previously
known low ionization absorption lines of MgII, and neither has been observed in
the Lyman-alpha line. The 21cm line observations provide information on column
densities, temperatures and kinematics of the thickest cold neutral clouds in
the absorbers.

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The categories of this paper are: chem-ph
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The categories of this paper are: plasm-ph
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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: atom-ph
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The categories of this paper are: cs
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The categories of this paper are: patt-sol
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The categories of this paper are: comp-gas
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The categories of this paper are: cond-mat
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The categories of this paper are: q-bio
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The categories of this paper are: q-fin
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The categories of this paper are: chao-dyn
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The categories of this paper are: stat
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The categories of this paper are: funct-an
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The categories of this paper are: econ
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The categories of this paper are: eess