Related papers: Broad emission lines for negatively spinning black…
X-ray irradiation of the accretion disc leads to strong reflection features, which are then broadened and distorted by relativistic effects. We present a detailed, general relativistic approach to model this irradiation for different…
If an accretion disk around a black hole is illuminated by hard X-rays from non-thermal coronae, fluorescent iron lines will be emitted from the inner region of the accretion disk. The emission line profiles will show a variety of strong…
Single-frequency emission from an accretion disk around a black hole is broadened into a line profile due to gravitational redshift and the motion of the disk's particles relative to the observer. The ensemble of relativistically broadened…
We describe a new code which can accurately calculate the relativistic effects which distort the emission from an accretion disc around a black hole. We compare our results for a disk which extends from the innermost stable orbit to…
Spectral features can arise by reflection of coronal X-rays on a black hole accretion disc. The resulting profile bears various imprints of strong gravitational field acting on the light emitting gas. The observed shape of the reflection…
Spin of an accreting black hole can be determined by spectroscopy of the emission and absorption features produced in the inner regions of an accretion disc. We discuss the method employing the relativistic line profiles of iron in the…
We consider a rapidly spinning black hole surrounded by an equatorial, geometrically thin, slowly accreting disk that is stationary and axisymmetric. We analytically compute the broadening of electromagnetic line emissions from the…
We have explored spectral line profiles due to spiral patterns in accretion discs around black holes. A parametrization was employed for the shape and emissivity of spiral waves, which can be produced by non-axisymmetric perturbations…
Double peaked broad emission lines in active galactic nuclei are generally considered to be formed in an accretion disc. In this paper, we compute the profiles of reprocessing emission lines from a relativistic, warped accretion disc around…
X-ray reflection off the accretion disc surrounding a black hole, together with the associated broad iron K$\alpha$ line, has been widely used to constrain the innermost accretion-flow geometry and black hole spin. Some recent measurements…
The profile of the fluorescent iron line from black hole accretion disks is a powerful diagnostic of black hole properties, such as spin and inclination. The state-of-the-art, however, considers an accretion disk whose angular momentum is…
We investigate the global properties of the radiation emitted by the accretion disk around Kerr black holes. Using the Kerr blackbody (KERRBB) numerical model, we build an analytic approximation of the disk emission features focusing on the…
The observed profile of spectral lines from a relativistic accretion disk can constrain parameters such as the disk geometry and the rotation of the central black hole. The formation of the spectral line in a disk generally has been modeled…
Relativistic emission lines generated by thin accretion disks around rotating black holes are an important diagnostic tool for testing gravity near the horizon. The iron K-line is of special importance for the interpretation of the X-ray…
During the spin-down phase of the life of a higher-dimensional black hole, the emission of particles on the brane exhibits a strong angular variation with respect to the rotation axis of the black hole. It has been suggested that this…
The reflection spectrum produced by a cold medium illuminated by X-ray photons is not isotropic and its shape depends on the emission angle. In the reflection spectrum of an accretion disk of a black hole, the value of the emission angle…
Inner accretion disc around a black hole provides a rare, natural probe to understand the fundamental physics of the strong gravity regime. A possible tilt of such a disc, with respect to the black hole spin equator, is important. This is…
We describe a program that we have embarked on to estimate the spins of stellar-mass black holes in X-ray binaries. We fit the continuum X-ray spectrum of the radiation from the accretion disk using the standard thin disk model, and extract…
The illumination pattern (or emissivity profile) of the accretion disc due to the reflection of X-rays in AGN can be understood in terms of relativistic effects on the rays propagating from a source in a corona surrounding the central black…
We address the ability of broad iron emission lines from black hole accretion disks to diagnose the spin of the black hole. Using a high-resolution 3-dimensional MHD simulation of a geometrically-thin accretion disk in a Pseudo-Newtonian…