Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multi-timescale X-ray reverberation mapping of accreting black holes   Accreting black holes show characteristic reflection features in their X-ray
spectrum, including an iron K$\alpha$ line, resulting from hard X-ray continuum
photons illuminating the accretion disk. The reverberation lag resulting from
the path length difference between direct and reflected emission provides a
powerful tool to probe the innermost regions around both stellar-mass and
supermassive black holes. Here, we present for the first time a reverberation
mapping formalism that enables modeling of energy dependent time lags and
variability amplitude for a wide range of variability timescales, taking the
complete information of the cross-spectrum into account. We use a pivoting
power-law model to account for the spectral variability of the continuum that
dominates over the reverberation lags for longer time scale variability. We use
an analytic approximation to self-consistently account for the non-linear
effects caused by this continuum spectral variability, which have been ignored
by all previous reverberation studies. We find that ignoring these non-linear
effects can bias measurements of the reverberation lags, particularly at low
frequencies. Since our model is analytic, we are able to fit simultaneously for
a wide range of Fourier frequencies without prohibitive computational expense.
We also introduce a formalism of fitting to real and imaginary parts of our
cross-spectrum statistic, which naturally avoids some mistakes/inaccuracies
previously common in the literature. We perform proof-of-principle fits to
Rossi X-ray Timing Explorer data of Cygnus X-1.

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The categories of this paper are: q-alg
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The categories of this paper are: q-fin
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The categories of this paper are: eess
3
The categories of this paper are: physics
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The categories of this paper are: ao-sci
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The categories of this paper are: econ
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The categories of this paper are: gr-qc
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The categories of this paper are: nlin
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The categories of this paper are: dg-ga
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The categories of this paper are: mtrl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
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The categories of this paper are: patt-sol
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The categories of this paper are: nucl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: q-bio