Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasi-Periodic Oscillations in Short Recurring Bursts of the Soft-Gamma
  Repeater J1550-5418   The discovery of quasi-periodic oscillations (QPOs) in magnetar giant flares
has opened up prospects for neutron star asteroseismology. The scarcity of
giant flares makes a search for QPOs in the shorter, far more numerous bursts
from Soft Gamma Repeaters (SGRs) desirable. In Huppenkothen et al (2013), we
developed a Bayesian method for searching for QPOs in short magnetar bursts,
taking into account the effects of the complicated burst structure, and have
shown its feasibility on a small sample of bursts. Here, we apply the same
method to a much larger sample from a burst storm of 286 bursts from SGR
J1550-5418. We report a candidate signal at 260 Hz in a search of the
individual bursts, which is fairly broad. We also find two QPOs at 93 Hz and
one at 127 Hz, when averaging periodograms from a number of bursts in
individual triggers, at frequencies close to QPOs previously observed in
magnetar giant flares. Finally, for the first time, we explore the overall
burst variability in the sample, and report a weak anti-correlation between the
power-law index of the broadband model characterising aperiodic burst
variability, and the burst duration: shorter bursts have steeper power law
indices than longer bursts. This indicates that longer bursts vary over a
broader range of time scales, and are not simply longer versions of the short
bursts.

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The categories of this paper are: hep-lat
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: eess
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The categories of this paper are: stat
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The categories of this paper are: physics
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ph
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The categories of this paper are: q-alg
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The categories of this paper are: cond-mat
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The categories of this paper are: alg-geom