Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The double radio source 3C343.1: A galaxy-QSO pair with very different
  redshifts   The strong radio source 3C343.1 consists of a galaxy and a QSO separated by
no more than about 0.25 arcsec. The chance of this being an accidental
superposition is conservatively 10^-8. The z=0.344 galaxy is connected to the
z=0.750 QSO by a radio bridge. The numerical relation between the two redshifts
is that predicted from previous associations. This pair is an extreme example
of many similar physical associations of QSOs and galaxies with very different
redshifts.

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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
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The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
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The categories of this paper are: mtrl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: quant-ph
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The categories of this paper are: stat
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The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
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The categories of this paper are: funct-an
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The categories of this paper are: q-fin
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The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom