Related papers: Local models of two-temperature accretion disc cor…
The energy that heats the magnetically closed solar corona originates in the complex motions of the massive photosphere. Turbulent photospheric convection slowly displaces the footpoints of coronal field lines, causing them to become…
The heating mechanism of a corona above an accretion disk in active galactic nuclei (AGNs) is still unknown. One possible mechanism is magnetic reconnection heating requiring energy equipartition between magnetic energy and gas energy in…
We present results of radiative transfer calculations of Compton scattering of polarized radiation in a corona above an accretion disk. The corona has a plane-parallel geometry and is assumed to be homogeneous with a fixed temperature. We…
We study the thermal structure of the widely adopted two-dimensional advection dominated accretion flow (ADAF) of Narayan & Yi (1995a). The critical radius for a given mass accretion rate, outside of which the optically thin hot solutions…
Context. Warm corona is a possible explanation for Soft X-ray Excess in Active Galactic Nuclei (AGN). This paper contains self consistent modeling of both: accretion disk with optically thick corona, where the gas is heated by…
We discuss in detail the broad band X-ray variability expected in Seyfert galaxies in the framework of a Compton cooled corona model. Variations in the optical depth tau of the corona cause spectral changes in the Comptonized emission in…
Recent observations at high spatial resolution have shown that magnetic flux cancellation occurs on the solar surface much more frequently than previously thought, and so this led Priest et al 2018 to propose magnetic reconnection driven by…
Spicules have been proposed as significant contributors to the mass and energy balance of the corona. While previous observations have provided a glimpse of short-lived transient brightenings in the corona that are associated with spicules,…
A number of X-ray binaries exhibit clear evidence for the presence of disk winds in the high/soft state. A promising driving mechanism for these outflows is mass loss driven by the thermal expansion of X-ray heated material in the outer…
We have modelled the X-ray emission from the young rapid rotator AB Doradus (P = 0.514 days) using as a basis Zeeman-Doppler maps of the surface magnetic field. This allows us to reconcile the apparently conflicting observations of a high…
We construct a disk-corona model which accounts for the optical-to-X-ray spectral properties of Seyfert nuclei and QSOs. We study emission spectrum emerging from a vertical disk-corona structure composed of two-temperature plasma by solving…
We simulate the evolution of cluster galaxies' hot interstellar medium (ISM) gas due to ram pressure and thermal conduction in the intracluster medium (ICM). At the density and temperature of the ICM, the mean free paths of ICM electrons…
We use a global magnetohydrodynamic simulation of a geometrically thin accretion disk to investigate the locality and detailed structure of turbulence driven by the magnetorotational instability (MRI). The model disk has an aspect ratio $H…
We study a model of an accretion disc surrounded by an extended corona of the temperature 10^7 - 10^8 K. This corona modifies the disk spectrum since it redirects a significant fraction of the emission from the central parts towards the…
We propose a novel one-dimensional model that includes both shock and turbulence heating and qualify how these processes contribute to heating the corona and driving the solar wind. Compressible MHD simulations allow us to automatically…
Cool, dense material is frequently observed to permeate the hot, tenuous solar corona in the form of prominences, spicules and coronal rain. Both the cool material and surrounding corona exist at temperatures that are effectively thermally…
The corona, a hot cloud of electrons close to the centre of the accretion disc, produces the hard X-ray power-law continuum commonly seen in luminous Active Galactic Nuclei (AGN). The continuum has a high-energy turnover, typically in the…
We study vertical structure of radiation pressure dominated disc with a hot corona. We include all the relevant processes like bound--free opacity and convection. We show that the presence of the corona modifies considerably the density and…
We perform direct numerical simulations of an externally driven two-dimensional magnetohydrodynamic system over extended periods of time to simulate the dynamics of a transverse section of a solar coronal loop. A stationary and large-scale…
Energetic X-ray radiations emitted from various accretion systems are widely considered to be produced by Comptonization in the hot corona. The corona and its interaction with the disc play an essential role in the evolution of the system…