Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Milliarcsec-scale radio structure of a matched sample of Seyfert 1 and
  Seyfert 2 galaxies   We have obtained mas-scale resolution very long baseline interferometry
(VLBI) images of a sample of Seyfert 1 and Seyfert 2 galaxies at 5 GHz
(wavelength, $\lambda$ = 6 cm). The Seyferts of the two types were chosen to be
matched in several orientation-independent properties, primarily in order to
rigorously test predictions of the unified scheme. We detected all the 15
objects that we observed. In this paper we describe the observations and data
reduction procedures, and present the VLBI radio images as well as simultaneous
Very Large Array images that we obtained for these 15 Seyferts.

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The categories of this paper are: q-fin
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The categories of this paper are: stat
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The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
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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: gr-qc
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The categories of this paper are: bayes-an
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The categories of this paper are: nlin
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: math-ph
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The categories of this paper are: math
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The categories of this paper are: cond-mat