Related papers: Optically Thick Outflows of Supercritical Accretio…
Radiative transfer equation in an accretion disk wind is examined analytically and numerically under the plane-parallel approximation in the subrelativistic regime of $(v/c)^1$, where $v$ is the wind vertical velocity. Emergent intensity is…
In this paper we present two efficient implementations of the diffusion approximation to be employed in Monte Carlo computations of radiative transfer in dusty media of massive circumstellar disks. The aim is to improve the accuracy of the…
Majority of ultraluminous X-ray sources (ULXs) are believed to be super-Eddington objects, providing a nearby prototype for studying an accretion in super-critical regime. In this work, we present the study of time-lag spectra of the ULX…
We study AGN line driven disc winds using time-dependent radiation hydrodynamics. The key criterion for determining wind launching is the coupling strength of the UV radiation field via the spectral lines of the gas. The strength of these…
The lack of unambiguous detections of atomic features in the X-ray spectra of ultraluminous X-ray sources (ULXs) has proven a hindrance in diagnosing the nature of the accretion flow. The possible association of spectral residuals at soft…
The nature of ultra-luminous X-ray sources (ULXs) has long been plagued by an ambiguity about whether the central compact objects are intermediate-mass (IMBH, >~ 10^3 M_sun) or stellar-mass (a few tens M_sun) black holes (BHs). The high…
The surface flux (and the corresponding observed flux) of a geometrically thick ``funnel'' shaped disk is computed taking into account the radiation impinging on the surface from other parts of the disk. It is found that the ratio of the…
I investigate the self-irradiation of intensively accreting circumstellar discs (backwarmed discs). It is modelled using the two-layer disc approach by Lachaume et al. (2003) that includes heating by viscous dissipation and by an external…
Accretion in black hole X-ray binaries is commonly believed to be supplied by the Roche lobe overflow or the stellar wind. The former is thought to form a geometrically thin disc while the diffuse wind could form a geometrically thick hot…
Multiwavelength observations of Galactic black hole transients have opened a new path to understanding the physics of the innermost parts of the accretion flows. While the processes giving rise to their X-ray continuum have been studied…
All disc-accreting astrophysical objects produce powerful outflows. In binaries containing neutron stars (NS) or black holes, accretion often takes place during violent outbursts. The main disc wind signatures during these eruptions are…
Contemporary radiation-magnetohydrodynamic simulation of the AGNs predicts presence of the hot and strong accretion disk wind, which gets unstable far from the central region and turns into gas clumps. These inner-wind and outer clumps may…
Photoevaporation is an important dispersal mechanism for protoplanetary disks. We conduct hydrodynamic simulations coupled with ray-tracing radiative transfer and consistent thermochemistry to study photoevaporative winds driven by…
Conventional X-ray methods use incoming plane waves and result in discrete diffraction patterns when scattered at crystals. Here we find, by a systematic method, incoming waveforms which exhibit discrete diffraction patterns when scattered…
Current models of the spectrum of X-rays reflected from accretion disks around black holes and other compact objects are commonly calculated assuming that the density of the disk atmosphere is constant within several Thomson depths from the…
Soft, potentially thermal spectral components observed in some ULXs can be fit with models for emission from cool, optically-thick accretion disks. If that description is correct, the low temperatures that are observed imply accretion onto…
Disc winds are a common feature in accreting astrophysical systems on all scales. In active galactic nuclei (AGN) and accreting white dwarfs (AWDs), specifically, radiation pressure mediated by spectral lines is a promising mechanism for…
The launch of high-spectral-resolution x-ray telescopes (Chandra, XMM) has provided a host of new spectral line diagnostics for the astrophysics community. In this paper we discuss Doppler-broadened emission line profiles from highly…
If massive stars form by disk accretion, then bipolar outflows should be generated as in the case of low-mass star formation. High accretion rates lead to high outflow rates and make the wind density very large near the protostar. We…
Radiation pressure-dominated accretion disks are predicted to exhibit strong density inhomogeneities on scales much smaller than the disk scale height, due to the nonlinear development of photon bubble instability. Radiation would escape…