Related papers: Iron Line Profiles in Strong Gravity
We present angle-dependent, broad-band intensity spectra from accretion disks around black holes of 10 M$_\odot$. In our computations disks are assumed to be slim, which means that the radial advection is taken into account while computing…
In this thesis a computational tool for modelling spectral features of X-ray sources in a strong gravitational field is developed. Six transfer functions, the gravitational and Doppler shift, lensing, emission angle, relative time delay,…
Accreting black holes often show iron line emission in their X-ray spectra. When this line emission is very broad or variable then it is likely to originate from close to the black hole. The theory and observations of such broad and…
According to the no-hair theorem, astrophysical black holes are fully characterized by their masses and spins and are described by the Kerr metric. This theorem can be tested observationally by measuring (at least) three different multipole…
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…
Recent observations show strong evidence for the presence of Doppler-shifted emission lines in the spectrum of both black hole candidates and active galactic nuclei. These lines are likely to originate from relativistic outflows (or jets)…
An intrinsically narrow line emitted by an accretion disk around a black hole appears broadened and skewed as a result of the Doppler effect and gravitational redshift. The fluorescent iron line in the X-ray band at 6.4-6.9keV is the…
We examined the profiles and polarization properties of emission lines originating from the extremely relativistic region of Kepler disks. Because the emission region is more localized to the inner part, e.g., a few times the black hole…
The fluorescent iron Ka line is a powerful observational probe of the inner regions of black holes accretion disks. Previous studies have assumed that only material outside the radius of marginal stability can contribute to the observed…
The fluorescent iron K$\alpha$ emission line profile provides an excellent probe of the innermost regions of active galactic nuclei. Fe XXV and Fe XXVI in diffuse plasma above the accretion disc can affect the X-ray spectrum by iron…
The observed iron K-alpha fluorescence lines in Seyfert galaxies provide strong evidence for an accretion disk near a supermassive black hole as a source of the line emission. Previous studies of line emission have considered only…
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…
Accreting black holes are believed to emit X-rays which then mediate information about strong gravity in the vicinity of the emission region. We report on a set of new routines for the Xspec package for analysing X-ray spectra of black-hole…
We calculate line emission from relativistic accretion tori around Kerr black holes and investigate how the line profiles depend on the viewing inclination, spin of the central black hole, parameters describing the shape of the tori, and…
Relativistic X-ray emission lines from the inner accretion disk around black holes are reviewed. Recent observations with the Chandra X-ray Observatory, X-ray Multi-Mirror Mission-Newton, and Suzaku are revealing these lines to be good…
Recent X-ray observations of Galactic Black Hole Candidates and AGNs and Seyfert galaxies reveal the broad emission lines in their spectra, which can arise in the innermost parts of accretion disks. Simulation indicates that at low…
The observed iron K-alpha fluorescence lines in Seyfert-1 galaxies provide strong evidence for an accretion disk near a supermassive black hole as a source of the line emission. These lines serve as powerful probes for examining the…
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…
Here we present a short overview and main results of our investigations of several effects which can induce shifts in the broad Fe K$\alpha$ line emitted from relativistic accretion disks around single and binary supermassive black holes.…
Here we discuss the effects of strong gravity that can be observed in electromagnetic spectra of active galactic nuclei (AGN). According to the unification model of an AGN, there is a supermassive black hole ($10^7 - 10^9 M_\odot$) in its…