Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Time evolution of flares in GRB 130925A: jet precession in black hole
  accretion system   GRB 130925A, composed of three gamma-ray emission episodes and a series of
orderly flares, has been detected by $Swift$, Fermi, Konus-$Wind$, and
$INTEGRAL$. If the third weakest gamma-ray episode can be considered as a giant
flare, we find that after the second gamma-ray episode observed by $INTEGRAL$
located at about 2000 s, there exists a positive relation between the time
intervals of the adjacent flares and the time since the episode. We suggest
that the second gamma-ray episode and its flares originate from the resumption
of the accretion process due to the fragments from the collapsar falling back,
such a relation may be related to a hyperaccretion disk around a precessed
black hole (BH). We propose that the origin and time evolution of the flares,
and the approximately symmetrical temporal structure and spectral evolution of
the single flare, can be explained well by the jet precession model
\citep{Liu2010}. In addition, the mass and spin of the BH can be constrained,
which indicates a stellar-mass, fast rotating BH located in the center of GRB
130925A.

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The categories of this paper are: eess
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The categories of this paper are: funct-an
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The categories of this paper are: q-fin
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The categories of this paper are: q-bio
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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: math
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
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The categories of this paper are: cs
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The categories of this paper are: stat
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The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: solv-int
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The categories of this paper are: hep-lat
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The categories of this paper are: econ