Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The GeV emission of PSR B1259-63 during its last three periastron
  passages observed by Fermi-LAT   PSR B1259-63 is a $\gamma$-ray emitting high mass X-ray binary system, in
which the compact object is a millisecond pulsar. The system has an orbital
period of 1236.7 d and shows peculiar $\gamma$-ray flares when the neutron star
moves out of the stellar disk of the companion star. The $\gamma$-ray flare
events were firstly discovered by using Fermi-LAT around the 2010 periastron
passage, which was repeated for the 2014 and 2017 periastron passages. We
analyze the Fermi-LAT data for all the three periastron passages and found that
in each flare the energy spectrum can be represented well by a simple power
law. The $\gamma$-ray light curves show that in 2010 and 2014 after each
periastron there are two main flares, but in 2017 there are four flares
including one precursor about 10 d after the periastron passage. The first main
flares in 2010 and 2014 are located at around 35 d after the periastron
passage, and the main flare in 2014 is delayed by roughly 1.7 d with respect to
that in 2010. In the 2017 flare, the source shows a precursor about 10 d after
the periastron passage, but the following two flares become weaker and lag
behind those in 2010 by roughly 5 d. The strongest flares in 2017 occurred 58 d
and 70 d after the periastron passage. These results challenge the previous
models.

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The categories of this paper are: atom-ph
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The categories of this paper are: hep-lat
3
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: alg-geom
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The categories of this paper are: eess
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The categories of this paper are: cond-mat
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The categories of this paper are: supr-con
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The categories of this paper are: quant-ph
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The categories of this paper are: math
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The categories of this paper are: nucl-th
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The categories of this paper are: gr-qc
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The categories of this paper are: cs
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: q-bio