80 citations · 164 across the 5 of their papers we have counts for
6 papers
The relativistic shift of narrow spectral features from black-hole accretion discs
T. Pechacek, M. Dovciak, V. Karas +1
Transient spectral features have been discovered in the X-ray spectra of Active Galactic Nuclei, mostly in the 5--7 keV energy range. Several interpretations were proposed for the…
X-ray Variability of Active Galactic Nuclei and the Flare Model
R. W. Goosmann, B. Czerny, A. -M. Dumont +4
Short-term variability of X-ray spectra has been reported for several Active Galactic Nuclei. Significant X-ray flux variations are observed within time scales down to 10^4 -- 10^5…
Polarization signatures of strong gravity in black-hole accretion discs
V. Karas, M. Dovciak, G. Matt
We discuss the effects of strong gravity on the polarization properties of a black hole accretion disc. The intrinsic polarization is computed taking into account light scattered o…
Polarization signatures of strong gravity in AGN accretion discs
M. Dovciak, V. Karas, G. Matt
The effects of strong gravity on the polarization of the Compton reflection from an X-ray illuminated accretion disc are studied. The gravitational field of a rotating black hole i…
Relativistic spectral features from X-ray illuminated spots and the measure of the black hole mass in AGN
M. Dovciak, S. Bianchi, M. Guainazzi +2
Narrow spectral features in the 5--6 keV range were recently discovered in the X-ray spectra of a few active galactic nuclei. We discuss the possibility that these features are due…
Magnetic fields around black holes
Z. Budinova, M. Dovciak, V. Karas +1
The electromagnetic field near a rotating black hole is being explored in educational style here. By employing analytic solutions for electrovacuum fields, we plot the surfaces of…