相关论文: Relativistic X-ray Lines from the Inner Accretion …
The horizon-scale images of black holes obtained with the Event Horizon Telescope have provided new probes of their metrics and tests of General Relativity. The images are characterized by a bright, near circular ring from the…
We consider thin accretion disks in the field of a class of rotating regular black holes. For this purpose, we obtain the radius of the innermost stable circular orbit, $r_{ISCO}$ and efficiency of accretion disk in converting matter into…
Accretion onto black holes often proceeds via an accretion disc or a temporary disc-like pattern. Variability features, observed in the light curves of such objects, and theoretical models of accretion flows suggest that accretion discs are…
The possibility that some of the observed X-ray and optical variability in active galactic nuclei and galactic black hole candidates is produced in accretion disks through the development of a self-organized critical state is reconsidered.…
Recent X-ray observations of microquasars and Seyfert galaxies reveal broad emission lines in their spectra, which can arise in the innermost parts of accretion disks. Simulations indicate that at low inclination angle the line is measured…
We review current challenges in understanding the values and origin of the spins of black holes in binaries. Thanks to recent advances in astrophysical instrumentation, the spins can now be measured using both gravitational waves emitted by…
In a previous paper, we presented an extension of our reflection model RELXILL_NK to include the finite thickness of the accretion disk following the prescription in Taylor & Reynolds (2018). In this paper, we apply our model to fit the…
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…
With the fundamental stress mechanism of accretion disks identified--correlated MHD turbulence driven by the magneto-rotational instability--it has become possible to make numerical simulations of accretion disk dynamics based on…
The spin measurement of black holes has important implications in physics and astrophysics. Regardless of the specific technique to estimate the black hole spin, all the current approaches assume that the space-time geometry around the…
The X-ray spectra of accreting stellar-mass black hole systems exhibit spectral features due to reflection, especially broad iron K alpha emission lines. We investigate the reflection by the accretion disc that can be expected in the…
Accretion discs around black holes in X-ray binary stars are warped if the spin axis of the black hole is not perpendicular to the binary orbital plane. They can also become eccentric through an instability involving a resonance with the…
Currently available information on fast variability of the X-ray emission from accreting collapsed objects constitutes a complex phenomenology which is difficult to interpret. We review the current observational standpoint for black-hole…
Here we present an overview of some of the most significant observational and theoretical studies of the broad Fe K{\alpha} spectral line, which is believed to originate from the innermost regions of relativistic accretion disks around…
We present a method to investigate relativistic effects arising from large masses. The method is non-perturbative and employs a mean-field approximation and gravitational lensing. Using this method and a basic model of disk galaxy, we find…
The properties of X-ray emission from accreting black holes are reviewed. The contemporary observational picture and current status of theoretical understanding of accretion and formation of X-ray radiation in the vicinity of the compact…
In this paper, we review our current efforts to test General Relativity in the strong field regime by studying the reflection spectrum of supermassive black holes. So far we have analyzed 11 sources with observations of NuSTAR, Suzaku,…
Observations of Galactic black hole sources are traditionally done in the classical X-ray range (2 -- 10 keV) due to sensitivity constraints. Most of the accretion power, however, is radiated above 10 keV and the study of these sources in…
Accretion disc model fitting to optical/UV quasar spectra requires that the highest mass black holes have the highest spin, with implications on the hierarchical growth of supermassive black holes and their host galaxies over cosmic time.…
We review the likely population, observational properties, and broad implications of stellar-mass black holes and ultraluminous x-ray sources. We focus on the clear empirical rules connecting accretion and outflow that have been established…