395 citations · 1.7k across the 42 of their papers we have counts for
29 papers · 1 filter
Interaction between disk and extended corona in a general relativistic framework
Sudeb Ranjan Datta, Michal Bursa, Michal Dovciak +1
The energy equilibrium between the corona and the underlying disk in a two-phase accretion flow sets a lower limit on the achievable photon index. A slab corona may not explain the…
Investigating the consistency of the shape and flux of X-ray reflection spectra in the hard state with an accretion disk reaching close to the black hole
Sudeb Ranjan Datta, Michal Dovčiak, Michal Bursa +3
The observed spectra from black hole (BH) X-ray binaries (XRBs) typically consist of two primary components: multitemperature blackbody (BB) originating from the accretion disk in…
Inferring the iron K emissivity profiles of accretion discs irradiated by extended coronae
Wenda Zhang, Michal Dovčiak, Michal Bursa +2
One of the most promising methods to measure the spin of an accreting black hole is fitting the broad iron K line in the X-ray spectrum. The line profile also depends on the geo…
First X-ray polarization measurement confirms the low black-hole spin in LMC X-3
Jiří Svoboda, Michal Dovčiak, James F. Steiner +109
X-ray polarization is a powerful tool to investigate the geometry of accreting material around black holes, allowing independent measurements of the black hole spin and orientation…
Accretion Disc Evolution in GRO J1655-40 and LMC X-3 with Relativistic and Non-Relativistic Disc Models
Anastasiya Yilmaz, Jiri Svoboda, Victoria Grinberg +3
Black hole X-ray binaries are ideal environments to study the accretion phenomena in strong gravitational potentials. These systems undergo dramatic accretion state transitions and…
Testing Relativistic Accretion Disk Models with GRO J1655-40
Anastasiya Yilmaz, Jiri Svoboda, Victoria Grinberg +3
Black hole X-ray binaries are ideal environments to test the accretion phenomena in the presence of strong gravitational potentials. KERRBB held an important place in the X-ray spe…
X-ray Polarimetry as a Tool to Measure the Black Hole Spin in Microquasars: Simulations of IXPE Capabilities
Romana Mikusincova, Michal Dovciak, Michal Bursa +5
Measurements of the angular momentum (spin) of astrophysical black holes are extremely important, as they provide information on the black hole formation and evolution. We present…
A theoretical study of the time-lags due to Comptonization and the constraints on the X-ray corona in AGN
W. Zhang, I. E. Papadakis, M. Dovčiak +2
We study the Fourier time-lags due to the Comptonization of disc-emitted photons in a spherical, uniform, and stationary X-ray corona, which located on the rotational axis of the b…
Investigating the X-ray polarization of lamp-post coronae in BHXRB
Wenda Zhang, Michal Dovčiak, Michal Bursa +3
High-sensitivity X-ray polarimetric observations of black hole X-ray binaries, which will soon become available with the launches of space-borne X-ray observatories with sensitive…
A combined timing/spectral study of IRAS 13224-3809 using XMM-Newton data
M. D. Caballero-Garcia, I. E. Papadakis, M. Dovciak +3
We present the results from an X-ray variability study of IRAS 13224-3809. This is probably the best source for X-ray reverberation studies since it is X-ray bright, extremely vari…
X-ray quasi-periodic oscillations in Lense-Thirring precession model -- II. variability of relativistic iron K line
Bei You, Piotr T. Życki, Adam Ingram +2
Reprocessing of primary X-ray emission in the accretion disk of black hole X-ray binaries (BHXRBs) produces the reflection spectrum, with the characteristic Fe K fluorescence li…
Towards a complete description of spectra and polarization of black hole accretion disks: albedo profiles and returning radiation
Roberto Taverna, Wenda Zhang, Michal Dovčiak +4
Accretion disks around stellar-mass black holes (BHs) emit radiation peaking in the soft X-rays when the source is in the thermal state. The emerging photons are polarized and, for…
The high energy universe at ultra-high resolution: the power and promise of X-ray interferometry
Phil Uttley, Roland den Hartog, Cosimo Bambi +24
We propose the development of X-ray interferometry (XRI), to reveal the universe at high energies with ultra-high spatial resolution. With baselines which can be accommodated on a…
Constraining the size of the corona with fully relativistic calculations of spectra of extended corona. I - the Monte Carlo radiative transfer code
Wenda Zhang, Michal Dovčiak, Michal Bursa
The size and geometry of the X-ray emitting corona in AGNs are still not well constrained. Dovčiak & Done (2016) proposed a method based on calculations assuming a point-like lamp-…
X-ray Reverberation Observational Modelling in Active Galactic Nuclei
M. D. Caballero-Garcia, M. Dovciak, M. Bursa +2
X-ray reverberation in Active Galactic Nuclei, believed to be the result of the reprocessing of coronal photons by the underlying accretion disc, has allowed us to probe the proper…
Super-Massive Black Hole mass estimation from bright flares
Vladimir Karas, Michal Bursa, Michal Dovciak +4
Super-Massive Black Holes reside in galactic nuclei, where they exhibit episodic bright flares due to accretion events. Taking into account relativistic effects, namely, the boosti…
The method of transfer functions to describe GR effects in spectra and polarisation from black-hole accretion disks
Vladimir Karas, Michal Bursa, Michal Dovciak
We briefly review a fruitful approach to compute a variety of radiation signatures of General Relativity (GR) originating from accretion disks in strong gravity. A set of transfer…
Testing the X-ray reverberation model KYNREFREV in a sample of Seyfert 1 Active Galactic Nuclei
M. D. Caballero-Garcia, I. E. Papadakis, M. Dovciak +4
We present the first results obtained by the application of the KYNREFREV-reverberation model, which is ready for its use in XSPEC. This model computes the time dependent reflectio…
On the search of the elusive Intermediate Mass Black-Holes
M. D. Caballero-Garcia, S. Fabrika, A. J. Castro-Tirado +4
Ultra-Luminous X-ray sources (ULXs) are accreting black holes for which their X-ray properties have been seen to be different to the case of stellar-mass black hole binaries. For m…
X-ray quasi-periodic oscillations in Lense--Thirring precession model - I. variability of relativistic continuum
Bei You, Michal Bursa, Piotr T. Życki
We develop a Monte-Carlo code to compute the Compton scattered X-ray flux arising from a hot inner flow which undergoes Lense-Thirring precession. The hot flow intercepts seed phot…
First results from the use of the relativistic and slim disc model SLIMULX in XSPEC
M. D. Caballero-Garcia, M. Bursa, M. Dovciak +3
Ultra-Luminous X-ray sources (ULXs) are accreting black holes for which their X-ray properties have been seen to be different to the case of stellar-mass black hole binaries. For m…
Testing wind as an explanation for the spin problem in the continuum-fitting method
Bei You, Odele Straub, Bozena Czerny +4
The continuum-fitting method is one of the two most advanced methods of determining the black hole spin in accreting X-ray binary systems. There are, however, still some unresolved…
Inner Disc Obscuration in GRS 1915+105 Based on Relativistic Slim Disc Model
K. Vierdayanti, A. Sadowski, S. Mineshige +1
We study the observational signatures of the relativistic slim disc of 10 M_sun black hole, in a wide range of mass accretion rate, mdot, dimensionless spin parameter, a_ast, and v…
The Hot and Energetic Universe: The close environments of supermassive black holes
Michal Dovciak, Giorgio Matt, Stefano Bianchi +22
Most of the action in Active Galactic Nuclei (AGN) occurs within a few tens of gravitational radii from the supermassive black hole, where matter in the accretion disk may lose up…