On the high energy cut-off of accreting sources: Is general relativity relevant?

@article{Tamborra2018OnTH,
  title={On the high energy cut-off of accreting sources: Is general relativity relevant?},
  author={Francesco Tamborra and I. E. Papadakis and Michal Dovvciak and J. Svoboda},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2018},
  volume={475},
  pages={2045-2050}
}
The hard X-ray emission observed in accreting compact sources is believed to be produced by inverse Compton scattering of soft photons arising from the accretion disc by energetic electrons thermally distributed above the disc, the so-called X-ray corona. Many independent observations suggest that such coronae should be compact and located very close to the black hole. In this case general relativistic (GR) effects should play an important role to the continuum X-ray emission from these sources… 

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References

SHOWING 1-10 OF 17 REFERENCES
Properties of AGN coronae in the NuSTAR era – II. Hybrid plasma
The corona, a hot cloud of electrons close to the centre of the accretion disc, produces the hard X-ray power-law continuum commonly seen in luminous Active Galactic Nuclei (AGN). The continuum has a
ON THE LAMPPOST MODEL OF ACCRETING BLACK HOLES
We study the lamppost model, in which the X-ray source in accreting black hole (BH) systems is located on the rotation axis close to the horizon. We point out a number of inconsistencies in the
Properties of AGN coronae in the NuSTAR era
The focusing optics of NuSTAR have enabled high signal-to-noise ratio spectra to be obtained from many X-ray bright active galactic nuclei (AGN) and galactic black hole binaries (BHB). Spectral
Understanding X‐ray reflection emissivity profiles in AGN: locating the X‐ray source
The illumination pattern (or emissivity profile) of the accretion disc due to the reflection of X-rays in active galactic nucleus can be understood in terms of relativistic effects on the rays
General relativistic modelling of the negative reverberation X-ray time delays in AGN
We present the first systematic physical modelling of the time-lag spectra between the soft (0.3–1 keV) and the hard (1.5–4 keV) X-ray energy bands, as a function of Fourier frequency, in a sample of
The hard X-ray spectrum of NGC 5506 as seen by NuSTAR
NuSTAR observed the bright Compton-thin, narrow-line Seyfert 1 galaxy, NGC 5506, for about 56 ks. In agreement with past observations, the spectrum is well fitted by a power law with Γ ∼ 1.9, a
Theoretical aspects of relativistic spectral features
The inner parts of black-hole accretion discs shine in X-rays which can be monitored and the observed spectra can be used to trace strong gravitational fields in the place of emission and along paths
A comprehensive analysis of the hard X-ray spectra of bright Seyfert galaxies
Hard X-ray spectra of 28 bright Seyfert galaxies observed with INTEGRAL were analysed together with the X-ray spectra from XMM–Newton, Suzaku and RXTE. These broad-band data were fitted with a model
An X-ray variable absorber within the Broad Line Region in Fairall 51
Fairall 51 is a polar-scattered Seyfert 1 galaxy, a type of active galaxies believed to represent a bridge between unobscured type-1 and obscured type-2 objects. Fairall 51 has shown complex and
X–rays from active galactic nuclei: relativistically broadened emission lines
  • A. Fabian
  • Physics
    Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences
  • 2002
TLDR
Current results indicate that the authors are studying accretion flows well within 6GM/c2, and the observational evidence for broad iron lines is reviewed, from ASCA to recent Chandra and XMM–Newton spectra.
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