Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Phase lags of quasi-periodic oscillations across source states in the
  low-mass X-ray binary 4U 1636-53   While there are many dynamical mechanisms and models that try to explain the
origin and phenomenology of the quasi-periodic oscillations (QPOs) seen in the
X-ray light curves of low-mass X-ray binaries, few of them address how the
radiative processes occurring in these extreme environments give rise to the
rich set of variability features actually observed in these light curves. A
step towards this end comes from the study of the energy and frequency
dependence of the phase lags of these QPOs. Here we used a methodology that
allowed us to study, for the first time, the dependence of the phase lags of
all QPOs in the range of 1 Hz to 1300 Hz detected in the low-mass X-ray binary
4U 1636-53 upon energy and frequency as the source changes its states as it
moves through the colour-colour diagram. Our results suggest that within the
context of models of up-scattering Comptonization, the phase lags dependencies
upon frequency and energy can be used to extract size scales and physical
conditions of the medium that produces the lags.

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The categories of this paper are: stat
20
The categories of this paper are: acc-phys
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The categories of this paper are: eess
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The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
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The categories of this paper are: dg-ga
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The categories of this paper are: econ
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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: hep-ex
32
The categories of this paper are: atom-ph
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The categories of this paper are: cmp-lg