Related papers: An extensive numerical survey of the correlation b…
The relation between the mass accretion rate onto the circumstellar disc and the rate of mass ejection by magnetically driven winds is investigated using three-dimensional magnetohydrodynamics simulations. Using a spherical cloud core with…
We have applied axisymmetric MHD simulations to investigate the impact of the accretion disk magnetic flux profile on the jet collimation. Using the ZEUS-3D code modified for magnetic diffusivity, our simulations evolve from an initial…
We follow numerically the time evolution of axisymmetric outflows driven magneto-centrifugally from the inner portion of accretion disks, from their launching surface to large, observable distances. Special attention is paid to the…
Rotating outflows from protostellar disks might trace extended magneto-hydrodynamic (MHD) disk winds (DWs), providing a solution to the angular momentum problem in disk accretion for star formation. In the jet system HH 212, a rotating…
Several observational evidences and deeper theoretical insights reveal that accretion and outflow/jet are strongly correlated. We model an advective disk-outflow coupled dynamics. We investigate the properties of the disk-outflow surface…
We investigate outflows from the disk-magnetosphere boundary of rotating magnetized stars in cases where the magnetic field of a star is bunched into an X-type configuration using axisymmetric and full 3D MHD simulations. Such configuration…
The existence of outflow in accretion flows is confirmed by observations and magnetohydrodynamics (MHD) simulations. In this paper, we study outflows of accretion flows in the presence of resistivity and toroidal magnetic field. The…
I present and discuss a unified scheme for jet launching that is based on stochastic dissipation of the accretion disk kinetic energy, mainly via shock waves. In this scheme, termed thermally-launched jet model, the kinetic energy of the…
We present an analytical solution of a highly magnetized jet/wind flow. The left side of the general force-free jet/wind equation (the "pulsar" equation) is separated into a rotating and a nonrotating term. The two equations with either…
We investigate the formation of an ideal magnetized jet that originates from a disk acting as a boundary by conducting axisymmetric MHD simulations. Our simulations demonstrate that the magnetized jet is consistently launched and reaches a…
In the current paradigm of star formation magnetic fields play a very central role. Indeed, they probably help or even channel the initial gravitational collapse of the parent molecular cloud. But their most spectacular effect is certainly…
Outflows and convective motions in accretion flows have been intensively discussed recently in the context of advection-dominated accretion flow (ADAF) based on two-dimensional (2D) and three-dimensional (3D) hydrodynamical simulations. We,…
This paper examines a new class of exact and self-consistent MHD solutions which describe steady and axisymmetric hydromagnetic outflows from the atmosphere of a magnetized and rotating central object with possibly an orbiting accretion…
The jets observed to emanate from many compact accreting objects may arise from the twisting of a magnetic field threading a differentially rotating accretion disk which acts to magnetically extract angular momentum and energy from the…
We present results of magnetohydrodynamic (MHD) simulations of jet formation and propagation, discussing a variety of astrophysical setups. In the first approach we consider simulations of relativistic MHD jet formation, considering jets…
An exact model for magnetized and rotating outflows, underpressured at their axis, is analysed by means of a nonlinear separation of the variables in the two-dimensional governing magnetohydrodynamic (MHD) equations for axisymmetric…
Observations of Young Stellar Objects (YSOs) systems reveal a wide diversity of jet properties, from well-collimated bipolar jets to uni-polar jets and systems with no detectable jet. Both prograde and counter-rotating jets are reported,…
An investigation is made of disk accretion of matter onto a rotating star with an aligned dipole magnetic field. A new aspect of this work is that when the angular velocity of the star and disk differ substantially we argue that the $\bf B$…
Observations of jets from young stellar objects reveal the asymmetric outflows from some sources. A large set of $2.5$D MHD simulations has been carried out for axisymmetric viscous/diffusive disc accretion to rotating magnetized stars for…
We present a self-similar, steady-state model describing both a magnetized accretion disc and a magnetohydrodynamic jet. We focus on the role of a hot corona in such a structure. This corona enables the disc to launch various types of jets.…