Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A test of the millisecond magnetar central engine model of GRBs with
  Swift data   A rapidly spinning, strongly magnetized neutron star (magnetar) has been
proposed as one possible candidate of the central engine of gamma-ray bursts
(GRBs). We systematically analyze the Swift/XRT light curves of long GRBs
detected before 2013 August, and characterize them into four categories based
on how likely they may harbor a magnetar central engine: Gold, Silver,
Aluminum, and Non-magnetar. We also independently analyze the data of short
GRBs with a putative magnetar central engine. We then perform a statistical
study of various properties of the magnetar samples and the non-magnetar
sample, and investigate whether the data are consistent with the hypothesis
that there exist two types of central engines. By deriving the physical
parameters of the putative magnetars, we find that the observations of the Gold
and Silver samples are generally consistent with the predictions of the
magnetar model. For a reasonable beaming factor for long GRBs, the derived
magnetar surface magnetic field $B_p$ and initial spin period $P_0$ fall into
the reasonable range. Magnetar winds in short GRBs, on the other hand, are
consistent with being isotropic. No GRB in the magnetar sample has a
beam-corrected total energy exceeding the maximum energy budget defined by the
initial spin energy of the magnetar, while some non-magnetar GRBs do violate
such a limit. With beaming correction, on average the non-magnetar sample is
more energetic and luminous than the magnetar samples. Our analysis hints that
millisecond magnetars are likely operating in a good fraction, but probably not
all, GRBs.

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The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
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The categories of this paper are: econ
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
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The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
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The categories of this paper are: stat
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The categories of this paper are: q-alg
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The categories of this paper are: plasm-ph