Detection of an imaginary QPO in AT2019wey whose frequency drops from ~5 Hz to ~1 Hz with rising phase lags as the source transitions through HIMS and LHS, showing U-shaped phase-lag spectrum in HIMS.
X-ray reverberation around accreting black holes
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
Luminous accreting stellar mass and supermassive black holes produce power-law continuum X-ray emission from a compact central corona. Reverberation time lags occur due to light travel time-delays between changes in the direct coronal emission and corresponding variations in its reflection from the accretion flow. Reverberation is detectable using light curves made in different X-ray energy bands, since the direct and reflected components have different spectral shapes. Larger, lower frequency, lags are also seen and are identified with propagation of fluctuations through the accretion flow and associated corona. We review the evidence for X-ray reverberation in active galactic nuclei and black hole X-ray binaries, showing how it can be best measured and how it may be modelled. The timescales and energy-dependence of the high frequency reverberation lags show that much of the signal is originating from very close to the black hole in some objects, within a few gravitational radii of the event horizon. We consider how these signals can be studied in the future to carry out X-ray reverberation mapping of the regions closest to black holes.
fields
astro-ph.HE 3years
2026 3verdicts
UNVERDICTED 3representative citing papers
Variable column density and covering factor of three ionized absorbers in clumpy disk winds explain the X-ray variability in I Zw 1 with stable corona.
Using ray-tracing simulations and simulation-based inference, the authors construct an AGN population that reproduces the cosmic X-ray background, number counts, and absorption properties, deriving an intrinsic Compton-thick fraction of 40±3%.
citing papers explorer
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An atypical X-ray variability component in the black hole candidate AT2019wey
Detection of an imaginary QPO in AT2019wey whose frequency drops from ~5 Hz to ~1 Hz with rising phase lags as the source transitions through HIMS and LHS, showing U-shaped phase-lag spectrum in HIMS.
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Strong X-ray Variability of I Zwicky 1: Obscuration from Clumpy Accretion-Disk Winds
Variable column density and covering factor of three ionized absorbers in clumpy disk winds explain the X-ray variability in I Zw 1 with stable corona.
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Population synthesis of active galactic nuclei based on the radiation-regulated unification model
Using ray-tracing simulations and simulation-based inference, the authors construct an AGN population that reproduces the cosmic X-ray background, number counts, and absorption properties, deriving an intrinsic Compton-thick fraction of 40±3%.