Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Discovery of Quasi-Periodic Oscillations in the Recurrent Burst Emission
  from SGR 1806-20   We present evidence for Quasi-Periodic Oscillations (QPOs) in the recurrent
outburst emission from the soft gamma repeater SGR 1806-20 using NASA's Rossi
X-ray Timing Explorer (RXTE) observations. By searching a sample of 30 bursts
for timing signals at the frequencies of the QPOs discovered in the 2004
December 27 giant flare from the source, we find three QPOs at 84, 103, and 648
Hz in three different bursts. The first two QPOs lie within $\sim$ 1$\: \sigma$
from the 92 Hz QPO detected in the giant flare. The third QPO lie within $\sim$
9$\: \sigma$ from the 625 Hz QPO also detected in the same flare. The detected
QPOs are found in bursts with different durations, morphologies, and
brightness, and are vindicated by Monte Carlo simulations, which set a lower
limit confidence interval $\geq 4.3 \sigma$. We also find evidence for
candidate QPOs at higher frequencies in other bursts with lower statistical
significance. The fact that we can find evidence for QPOs in the recurrent
bursts at frequencies relatively close to those found in the giant flare is
intriguing and can offer insight about the origin of the oscillations. We
confront our finding against the available theoretical models and discuss the
connection between the QPOs we report and those detected in the giant flares.
The implications to the neutron star properties are also discussed.

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The categories of this paper are: nucl-ex
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The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
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The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
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The categories of this paper are: hep-th
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The categories of this paper are: acc-phys
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The categories of this paper are: cmp-lg
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The categories of this paper are: patt-sol
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The categories of this paper are: gr-qc
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The categories of this paper are: physics
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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: adap-org
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The categories of this paper are: econ