Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The identification of the long-period X-ray pulsar 1WGA J1958.2+323 with
  a Be-star/X-ray binary   We present the results of optical observations performed between May and
September 1998 of the stars within the position error circle of the recently
discovered 12min pulsating X-ray source 1WGA J1958.2+3232. Based on photometry
and slitless spectroscopy, we selected a likely optical counterpart, which was
subsequently determined to be a m_V=15.7 B0Ve star, the spectral properties of
which are in good agreement with the X-ray results. The proposed optical
counterpart shows several H, He and Fe emission-lines, while the interstellar
absorption spectral features place the star at a distance of about 800 pc.The
inferred X-ray luminosity for this distance is about 10^33 erg s^-1 in the
2--10 keV band. We conclude that 1WGA J1958.2+3232 is a likely new long-period
low-luminosity accreting neutron star in a Be-star/X-ray binary system.

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The categories of this paper are: stat
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The categories of this paper are: hep-ph
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
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The categories of this paper are: hep-ex
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The categories of this paper are: ao-sci
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The categories of this paper are: supr-con
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The categories of this paper are: adap-org
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The categories of this paper are: chem-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: patt-sol
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The categories of this paper are: solv-int
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The categories of this paper are: bayes-an
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The categories of this paper are: funct-an