Related papers: An accretion disk-outflow model for hysteretic sta…
The growing evidence for supermassive black holes in the centres of nearby galaxies has brought into sharper focus the question of why elliptical galaxies, rich in hot gas, do not possess quasar-like luminosities. Recent studies suggest…
We study the energetics of the accretion-induced outflow and then plausible jet around black holes/compact objects using a newly developed disc-outflow coupled model. Inter-connecting dynamics of outflow and accretion essentially upholds…
We investigate the X-ray origin in FR Is using the radio, submillimetre, optical, and {\em Chandra} X-ray data of a small sample consisting of eight FR I sources. These sources are very dim, with X-ray luminosities $L_{\rm X}/L_{\rm Edd}…
The recent {\em Chandra} observation of the radio source at the center of our Galaxy, Sgr A$^*$, puts new constraints on its theoretical models. The spectrum is very soft, and the source is rapidly variable. We consider different models to…
We evolve two high-resolution general relativistic magnetohydrodynamic (GRMHD) simulations of advection-dominated accretion flows around non-spinning black holes (BHs), each over a duration $\sim 3\times 10^5\,GM_{\rm BH}/c^3$. One model…
Current theoretical models for the outflows/jets from AGN, X-ray binaries and young stellar objects involve large-scale magnetic fields threading an underlying accretion disk. We suggest that such a disk is subjected to warping instability…
Soft and hard spectral states of X-ray transient sources reflect two modes of accretion, accretion via a geometrically thin, optically thick disk or an advection-dominated accretion flow (ADAF). The luminosity at transition between these…
In this paper, the self-similar solution of resistive advection dominated accretion flows (ADAF) in the presence of a pure azimuthal magnetic field is investigated. The mechanism of energy dissipation is assumed to be the viscosity and the…
Rapid, large amplitude variability at optical to X-ray wavelengths is now seen in an increasing number of Seyfert galaxies and luminous quasars. The variations imply a global change in accretion power, but are too rapid to be communicated…
Radiatively inefficient accretion flows (RIAFs) are common feature of low-luminosity accretion flows, including quiescent states of X-ray binaries and low-lunimosity active galactic nuclei. Thermally driven winds are expected from such hot…
We examine the effects of a global magnetic field and outflow on radiatively inefficient accretion flow (RIAF) in the presence of magnetic resistivity. We find a self-similar solutions for the height integrated equations that govern the…
We present the effects of ordered large scale magnetic field on the structure of supercritical accretion flow in the presence of outflow. In the cylindrical coordinates ($r, \varphi,z$), We write the 1.5 dimensional, the steady state…
The advent of the new generation of X-ray telescopes yielded a significant step forward in our understanding of ionised absorption generated in the accretion discs of X-ray binaries. It has become evident that these relatively weak and…
We review some of the properties of Advection-Dominated Accretion Flow (ADAF) models and show that they successfully describe many astrophysical systems. Despite these successful applications some fundamental problems still remain to be…
Magnetically-arrested disks (MADs) appear when accretion flows are supplied with a sufficient amount of magnetic flux. In this work, we use results of magnetohydrodynamic simulations to set the configuration of the magnetic field and…
Large scale magnetic field threading an accretion disk is a key ingredient in the jet formation model. The most attractive scenario for the origin of such a large scale field is the advection of the field by the gas in the accretion disk…
We present global solutions of optically thin, two-temperature black hole accretion disks incorporating magnetic fields. We assume that the {\pi}{\phi}-component of the Maxwell stress is proportional to the total pressure, and prescribe the…
The results of 3D modelling of the flow structure in the classical symbiotic system Z~Andromedae are presented. Outbursts in systems of this type occur when the accretion rate exceeds the upper limit of the steady burning range. Therefore,…
We develop a new method to describe the accretion flow in the corona above a thin disk around a black hole in vertical and radial extent. The model is based on the same physics as the earlier one-zone model, but now modified including…
The predicted radio flux for nearby ellipticals by the canonical ADAF(advection-dominated accretion flow) model is well above the observations. If the mass accretion rate favored by the numerical simulation were adopted, the ADAF model…