Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Correlated X-ray spectral and fast-timing behaviour of 4U 1636-53   We present a study of the persistent X-ray emission from the low-mass X-ray
binary 4U 1636-53 based ont he entire archival EXOSAT ME data set. We per-
formed a homogeneous analysis of all five EXOSAT observations in terms of the
correlated rapid X-ray variability and X-ray spectral properties by means of
power spectra, and colour-colour and hardness-intensity diagrams, respectively.
Over the years we find similar patterns in the colour-colour and
hardness-intensity diagrams, but small shifts in their postions occur. We find
one case of an island-banana transition. On all but one occasion the
differences in colour are smaller than 5%. Between the two 'island state' data
sets, we find a shift of 8 % in the soft colour, which must be at least partly
intrinsic. Clear correlations are present between the X-ray colours (which are
governed by the mass accretion rate) and the power spectrum. With increasing
mass accretion rate the fractional rms amplitude of the power-law shaped power
spectral component that dominates the power spectra below ~1 Hz rises, while
the band-limited noise component at higher frequencies drops. The cut-off
frequency of the band-limited component increases whn its amplitude decreases.
This is reminiscent of the behaviour of black hole candidates in the low state.

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The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph
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The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-ex
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The categories of this paper are: eess
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The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ph
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The categories of this paper are: adap-org
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The categories of this paper are: quant-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: physics