Related papers: Advective Flow Paradigm And Microquasar GRS1915+10…
Accretion and outflows are common in systems which include black holes. Especially important is the case of the well known micro-quasar GRS1915+105 in our own galaxy, where super-luminal outflows are detected. We present a few observation…
A new code and methodology are introduced for solving the general relativistic magnetohydrodynamic (GRMHD) equations in fixed background spacetimes using time-explicit, finite-volume discretization. The code has options for solving the…
Gas accretion and radial flows are key ingredients of the chemical evolution of spiral galaxies. They are also tightly linked to each other (accretion drives radial flows, due to angular momentum conservation) and should therefore be…
We investigate the association between the accretion disk during radio plateau state and the following superluminal relativistic radio jets with peak intensity varies from 200 mJy to 1000 mJy observed over a period of five years and present…
We present the properties of relativistic, inviscid, low angular momentum, advective accretion flow in a $f(R)$ gravity theory that satisfactorily mimics the asymptotically flat vacuum solutions of the Einstein's equations. With this, we…
Recent work on advection-dominated accretion flows (ADAFs) is reviewed. The article concentrates on an optically thin branch of ADAFs which is present at mass accretion rates below a critical value $\sim(10^{-2}-10^{-1})$ the Eddington…
Microquasars are compact binary systems hosting collimated relativistic jets. They have long been proposed as cosmic-ray accelerators, probed via the gamma-ray emission produced by relativistic particles. However, the observational evidence…
We present a modified description of advection-dominated accretion flows (ADAF) with a geometrical viscosity. A simplified treatment of the dynamics of the flow in the inner relativistic part is suggested and results are compared with the…
The hydrodynamics of a variant of classical Bondi-Hoyle-Lyttleton accretion is investigated: a totally absorbing sphere moves at various Mach numbers (3 and 10) relative to a medium, which is taken to be an ideal gas having a density…
Observations of the hot gas, which is surrounding Sgr A* and a few other nearby galactic nuclei, imply that mean free paths of electron and proton are comparable to gas capture radius. So, hot accretion flows likely proceed under week…
We introduce a novel artificial compressibility technique to approximate the incompressible Navier-Stokes equations with variable fluid properties such as density and dynamical viscosity. The proposed scheme used the couple pressure and…
We review basic properties of advection-dominated accretion flows (ADAFs) and their applications to astrophysical systems ranging from Galactic binary systems to galactic nuclei. A new classification scheme for low-luminosity, X-ray bright…
We present the first dynamical model of plasma accretion onto traversable wormholes by performing General Relativistic magneto-hydrodynamical (GRMHD) simulations of the flow on both sides of the wormhole. We evolve the ideal MHD equations…
We present a magneto-hydrodynamic model developed for investigations of advective non-stationary, asymmetric Keplerian accretion disks in the normal magnetic field. The introduced model allows us to trace the evolution in different fixed…
Using non-linear time series analysis, along with surrogate data analysis, it is shown that the various types of long term variability exhibited by the black hole system GRS 1915+105, can be explained in terms of a deterministic non-linear…
We obtained global transonic solutions representing optically thin advection-dominated accretion flow by solving the full set of differential equations describing such systems. We found that far from the sonic point self-similar solutions…
A model for advection-dominated accretion flows (ADAFs) in a global magnetic field is proposed. In contrast to the well known ADAF models in which the viscosity of a fluid determines both angular momentum transfer and energy dissipation in…
We investigate the dependency of the inflow-wind structure of the hot accretion flow on the kinematic viscosity coefficient. In this regard, we propose a model for the kinematic viscosity coefficient to mimic the behavior of the…
The metal-poor gas continuously accreting onto the discs of spiral galaxies is unlikely to arrive from the intergalactic medium (IGM) with exactly the same rotation velocity as the galaxy itself and even a small angular momentum mismatch…
Microquasars are galactic black hole binary systems with radio jets which can sometimes be spatially resolved to show superluminal motion. The first and best known of this class of objects is GRS 1915+105, the brightest accreting source in…