Related papers: Energy-dependent variability from accretion flows
We develop a model of an accretion disc in which the variability induced at a given radius is governed by a damped harmonic oscillator at the corresponding epicyclic frequency. That variability induces both linear and non-linear responses…
We consider the properties of a hyperaccretion model for gamma-ray bursts (GRBs) at the late time when the mass supply rate is expected to decrease with time. We point out that the region in the vicinity of the accretor and the accretor…
Multiwavelength variability data, combined with spectral-timing analysis techniques, provides information about the causal relationship between different physical components in accreting black holes. Using fast-timing data and long-term…
The X-ray variability in the soft X-ray spectral state of black hole binaries is primarily characterized by a power-law noise (PLN), which is thought to originate from the propagation of the modulation in the mass accretion rate of a…
Two-dimensional (axially symmetric) numerical hydrodynamical calculations of accretion flows which cannot cool through emission of radiation are presented. The calculations begin from an equilibrium configuration consisting of a thick torus…
Two-dimensional accretion flows near black holes have been investigated by time-dependent hydrodynamical calculations. We assume that the flow is axisymmetric and that radiative losses of internal energy are negligible, so that the disc is…
Using the methods originally developed for Random Matrix Theory we derive an exact mathematical formula for number variance (introduced in [4]) describing a rigidity of particle ensembles with power-law repulsion. The resulting relation is…
Thermal models have been used to successfully describe the hadron yields from heavy ion collisions at a variety of energies. For root(S)<17 GeV this has usually been done using yields integrated over 4pi but at the higher energies available…
The dramatic hard-soft spectral transition in Black Hole Binaries is important as it is associated with the collapse of the jet and with the strongest low frequency QPOs. These transition spectra (intermediate and very high state: VHS) are…
The variability of the Fe K alpha line near 6.5 keV seems to be reduced compared to the variability of the hard X-rays which presumably drive the line emission. This is observed both in active galactic nuclei and galactic black hole…
Using the flux resolved spectroscopy for the first time, we analyse the RXTE/PCA data of the black hole X-ray binaries GRS 1915+105 and IGR J17091-3624, when both sources show large amplitude, quasi-regular oscillations in 2.0-60.0 keV…
Magnetic cataclysmic variables are close binary systems containing a strongly magnetized white dwarf that accretes matter coming from an M-dwarf companion. High-energy radiation coming from those objects is emitted from the accretion column…
We present preliminary results of our study of the impact of strong gravity effects on properties of the high energy radiation produced in accretion flows around supermassive black holes. We refine a model of the X-ray emission from a hot…
We obtain global solutions of radiatively inefficiently accretion flows around black holes. Whether and where convection develops in a flow are self-consistently determined with the mixing-length theory. The solutions can be divided into…
Results are presented from a time--dependent, numerical investigation of spherical accretion onto black holes, within the framework of relativistic radiation hydrodynamics. We have studied the stability of self--consistent, stationary…
Depending on the astrophysical source and its environment, the accretion flows can exhibit a variety of behaviors and characteristics in accordance with the type of solutions. We study low-angular-momentum accretion flows onto black holes…
It is believed that the spectral state transitions of the outbursts in X-ray binaries (XRBs) are triggered by the rise of the mass accretion rate due to underlying disc instabilities. Recent observations found that characteristics of disc…
We treat transformation properties of external radiation fields in the proper frame of a plasma moving with constant speed. The specific spectral energy densities of external isotropic and accretion-disk radiation fields are derived in the…
The optical/ultraviolet (UV) variability of quasars has been discovered to be correlated with other quasar properties, such as luminosity, black hole mass and rest-frame wavelength. However,the origin of variability has been a puzzle so…
We report flow measurements in rotating Rayleigh--B\'enard convection in the rotationally-constrained geostrophic regime. We apply stereoscopic particle image velocimetry to measure the three components of velocity in a horizontal…