Related papers: Angular momentum transport through magnetic accret…
The formation of binary stars is highly influenced by magnetic fields, which play a crucial role in transporting angular momentum. We conducted three-dimensional numerical simulations of binary star accretion via a circumbinary disk, taking…
Strong magnetic fields play a crucial role in the removal of angular momentum from collapsing clouds and protostellar discs and are necessary for the formation of disc winds as well as jets from the inner disc and indeed, strong large-scale…
Observations of stellar rotation show that low-mass stars lose angular momentum during the main sequence. We simulate the winds of Sun-like stars with a range of rotation rates, covering the fast and slow magneto-rotator regimes, including…
Non-thermal X-ray emission in compact accretion engines can be interpreted to result from magnetic dissipation in an optically thin magnetized corona above an optically thick accretion disk. If coronal magnetic field originates in the disk…
We study global transonic solution for a relativistic, magnetized, viscous advective accretion flow around a rotating black hole, incorporating the effects of mass and angular momentum loss through winds. Our model considers dominant…
The orbital angular momentum of individual stars in galactic discs can be permanently changed through torques from transient spiral patterns. Interactions at the corotation resonance dominate these changes and have the further property of…
I review, from an observational perspective, the interactions of accretion discs with magnetic fields in cataclysmic variable stars. I start with systems where the accretion flows via a stream, and discuss the circumstances in which the…
We examine the angular momentum transport properties of disks composed of macroscopic particles whose velocity dispersions are externally enhanced (``stirred''). Our simple Boltzmann equation model serves as an analogy for unmagnetized…
The observations and simulations have revealed that large-scale magnetic field and outflows can exist in the inner regions of an advection-dominated accretion disc where the resistive diffusion may also be important. In the present paper,…
Millisecond pulsars are rather weakly-magnetized neutron stars which are thought to have been spun up by disc accretion, with magnetic linkage between the star and the disc playing a key role. Their spin history depends sensitively on…
We investigate under which conditions cold, fan-shaped winds can be steadily launched from thin (Keplerian) accretion discs. Such winds are magneto-centrifugal winds launched from a thin annulus in the disc, along open magnetic field lines…
Study of observed spin evolution of long-period X-ray pulsars challenges quasi-spherical and Keplerian disk accretion scenarios. It suggests that the magnetospheric radius of the neutron stars is substantially smaller than Alfven radius and…
We investigate the radial transport of magnetic flux in a thin accretion disc, the turbulence being modelled by effective diffusion coefficients (viscosity and resistivity). Both turbulent diffusion and advection by the accretion flow…
We study the 2-D, time-dependent hydrodynamics of radiation-driven winds from luminous accretion disks threaded by a strong, large-scale, ordered magnetic field. The radiation force is due to spectral lines and is calculated using a…
Channelled fragmented downflows are ubiquitous in magnetized atmospheres, and have been recently addressed from an observation after a solar eruption. We study the possible back-effect of the magnetic field on the propagation of confined…
Recent discoveries have confirmed the existence of a large population of X-ray sources fuelled by accretion from the stellar wind of an OB supergiant. Such systems are powerful laboratories to study many aspects of astrophysics. Over the…
A new type of wind - a conical wind - has been discovered in axisymmetric magnetohydrodynamic simulations of the disk-magnetosphere interaction in cases where the magnetic field of the star is bunched into an X-type configuration. Such a…
Convection has been discussed in the field of accretion discs for several decades, both as a means of angular momentum transport and also because of its role in controlling discs' vertical structure via heat transport. If the gas is…
A protostellar disk is threaded by a static magnetic field that is perpendicular to the disk-surface. The magnetic field acts to brake the protostellar disk and cause the disk material to move towards the protostar. General analytic…
The angular momentum of galactic discs in semi-analytic models of galaxy formation is usually updated in time as material is accreted to the disc by adopting a constant dimensionless spin parameter and little attention is paid to the…