Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multi-waveband detection of quasi-periodic pulsations in a stellar flare
  on EK Draconis observed by XMM-Newton   Context. Quasi-periodic pulsations (QPPs) are time variations in the energy
emission during a flare that are observed on both the Sun and other stars and
thus have the potential to link the physics of solar and stellar flares. Aims.
To characterise the QPPs detected in an X-ray flare on the solar analogue, EK
Draconis, which was observed by XMM-Newton. Methods. We use wavelet and
autocorrelation techniques to identify the QPPs in a detrended version of the
flare. We also fit a model to the flare based on an exponential decay combined
with a decaying sinusoid. The flare is examined in multiple energy bands.
Results. A statistically significant QPP is observed in the X-ray energy band
of 0.2-12.0 keV with a periodicity of 76+/-2 min. When this energy band is
split, a statistically significant QPP is observed in the low-energy band
(0.2-1.0 keV) with a periodicity of 73+/-2 min and in the high-energy band
(1.0-12.0 keV) with a periodicity of 82+/-2 min. When fitting a model to the
time series the phases of the signals are also found to be significantly
different in the two energy bands (with a difference of 1.8+/-0.2 rad) and the
high-energy band is found to lead the low-energy band. Furthermore, the first
peak in the cross-correlation between the detrended residuals of the low- and
high-energy bands is offset from zero by more than 3{\sigma} (4.1+/-1.3 min).
Both energy bands produce statistically significant regions in the wavelet
spectrum, whose periods are consistent with those listed above. However, the
peaks are broad in both the wavelet and global power spectra, with the wavelet
showing evidence for a drift in period with time, and the difference in period
obtained is not significant. etc...

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The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
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The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
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The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
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The categories of this paper are: quant-ph
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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-alg
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The categories of this paper are: nlin