Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The discovery and study of the optical counterparts of the transient
  X-ray pulsars RXJ0052.1-7319 and XTEJ0111.2-7317 in the SMC   We report on the discovery and confirmation of the optical counterparts of
the two transient X-ray pulsars, RXJ0052.1-7319 and XTEJ0111.2-7317. In the
narrow (~3" radius) X-ray error circle of RXJ0052.1-7319 we found a V=14.6
(B-V=0.1) 09.5IIIe (a classification as a B0Ve star is also possible, since the
luminosity class depends on the uncertainty on the adopted reddening). Medium
resolution spectra for this object show Balmer lines in emission with an
equivalent width of Halpha=-12/-16A. In the X-ray error box of XTEJ0111.2-7317
we found a relatively bright object (V=15.4, B-V=0.06) which has been
classified as a B0.5-B1Ve star and that was later confirmed by Coe et al.
(2000) as the most plausible counterpart for XTEJ0111.2-7317. Also in this case
we easily detect Balmer emission lines with an Halpha equivalent width of about
-21A. There is also evidence for the presence of a surrounding nebula, possibly
a supernova remnant. A further bright B0Ve star was found just outside the
X-ray error circle of XTEJ0111.2-7317. We discuss the implication of these
results in the light of the current knowledge of Be/X-ray binary systems in the
Magellanic Clouds and within our Galaxy.

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The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-ex
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The categories of this paper are: nlin
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The categories of this paper are: q-alg
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The categories of this paper are: adap-org
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The categories of this paper are: physics
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The categories of this paper are: q-fin
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
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The categories of this paper are: q-bio
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The categories of this paper are: acc-phys
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th