Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Swift discovery of the orbital period of the HMXB IGR J015712-7259 in
  the Small Magellanic Cloud   In the last years the hard X-ray astronomy has made a significant step
forward, thanks to the monitoring of the IBIS/ISGRI telescope on board the
INTEGRAL satellite and of the Burst Alert Telescope (BAT) on board of the Swift
observatory. This has provided a huge amount of novel information on many
classes of sources. We have been exploiting the BAT survey data to study the
variability and the spectral properties of the new high mass X-ray binary
sources detected by INTEGRAL. In this letter we investigate the properties of
IGR J015712-7259. We perform timing analysis on the 88-month BAT survey data
and on the XRT pointed observations of this source. We also report on the
broad-band 0.2-150 keV spectral analysis. We find evidence for a modulation of
the hard-X-ray emission with period P_o=35.6 days. The significance of this
modulation is 6.1 standard deviations. The broad band spectrum is modeled with
an absorbed power law with photon index Gamma 0.4 and a steepening in the BAT
energy range modeled with a cutoff at an energy of ~13 keV.}

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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: hep-th
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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: quant-ph
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The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: cond-mat
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: cs
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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin
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The categories of this paper are: econ