相关论文: Looking into the inner black hole accretion disc w…
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…
Reynolds & Begelman (1997) have recently proposed a model in which the broad and extremely redshifted iron line seen during a deep minimum of the light curve of the Seyfert 1 galaxy MCG-6-30-15 originates from matter spiralling into a…
Most black hole binaries show large changes in X-ray luminosity caused primarily by variations in mass accretion rate. An important question for understanding black hole accretion and jet production is whether the inner edge of the…
We discuss constraints on the physics of the inner accretion disk, as well as the properties of the black hole itself, that can be derived by a detailed examination of the relativistically broadened spectral features (especially the…
We discuss constraints on black hole spin and spin-related astrophysics as derived from X-ray spectroscopy. After a brief discussion about the robustness with which X-ray spectroscopy can be used to probe strong gravity, we summarize how…
I review the current status of X-ray reflection (a.k.a. broad iron line) based black hole spin measurements. This is a powerful technique that allows us to measure robust black hole spins across the mass range, from the stellar-mass black…
Spectroscopy of X-ray emission lines emitted in accretion discs around supermassive black holes is one of the most powerful probes of the accretion flow physics and geometry, while also providing in principle observational constraints on…
We show that disc continuum fitting can be used to constrain black hole spin in a subclass of Narrow Line Seyfert 1 (NLS1) AGN as their low mass and high mass accretion rate means that the disc peaks at energies just below the soft X-ray…
Recent X-ray observations have shown broad, skewed iron line emission from Seyfert 1 galaxies which is explained by the emission being fluorescence on a disk close to a black hole. During one interval, the line in MCG--6-30-15 was so broad…
In this paper we present a fully relativistic approach to modelling both the continuum emission and the reflected fluorescent iron line from a primary X-ray source near a Kerr black hole. The X-ray source is located above an accretion disc…
X-rays are emitted from the corona above the orbiting matter of the accretion disk and travel either directly to us or illuminate the disk. This illumination of the inner disk is enhanced by gravitational light bending, which focuses the…
Recent X-ray spectroscopy made with ASCA have shown broad, skewed iron line emission from Seyfert-1 galaxies. The large extent of the red tail allows probing of the innermost regions of the black hole's accretion disc. A model of line…
We present Fe Kalpha line profiles from and images of relativistic discs with finite thickness around a rotating black hole using a novel code. The line is thought to be produced by iron fluorescence of a relatively cold X-ray illuminated…
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…
The black-hole binary system LMC X-3 has been observed by virtually every X-ray mission since the inception of X-ray astronomy. Among the persistent sources, LMC X-3 is uniquely both habitually soft and highly variable. Using a fully…
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 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…
The relativistically broad X-ray iron line seen in many AGN spectra is thought to originate from the central regions of the putative black hole accretion disk. Both the line profile and strength will vary in response to rapid variability of…
There is growing evidence from both spectral and timing properties that there is a truncated inner accretion disc in low mass accretion rate Galactic black hole systems. The detection of extremely smeared relativistic iron lines in some of…
One of the most promising methods to measure the spin of an accreting black hole is fitting the broad iron K$\alpha$ line in the X-ray spectrum. The line profile also depends on the geometry of the hard X-ray emitting corona. To put…