Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: XMM-Newton discovery of 2.6 s pulsations in the soft gamma-ray repeater
  SGR 1627-41   After nearly a decade of quiescence, the soft gamma-ray repeater SGR 1627-41
reactivated on 2008 May 28 with a bursting episode followed by a slowly
decaying enhancement of its persistent emission. To search for the still
unknown spin period of this SGR taking advantage of its high flux state, we
performed on 2008 September 27-28 a 120 ks long X-ray observation with the
XMM-Newton satellite. Pulsations with P = 2.594578(6) s were detected at a
higher than 6-sigma confidence level, with a double-peaked pulse profile. The
pulsed fraction in the 2-12 keV range is 19% +/- 3% and 24% +/- 3% for the
fundamental and the second harmonic, respectively. The observed 2-10 keV flux
is 3.4E-13 erg/cm^2/s, still a factor of ~ 5 above the quiescent
pre-burst-activation level, and the spectrum is well fitted by an absorbed
power law plus blackbody model (photon index Gamma = 0.6, blackbody temperature
kT = 0.5 keV, and absorption nH = 1.2E+23 cm^-2). We also detected a shell of
diffuse soft X-ray emission which is likely associated with the young supernova
remnant G337.0-0.1.

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The categories of this paper are: math
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The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: q-bio
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The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
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The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
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The categories of this paper are: nlin
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The categories of this paper are: math-ph
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ex
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The categories of this paper are: econ
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The categories of this paper are: supr-con
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The categories of this paper are: alg-geom
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The categories of this paper are: stat