相关论文: Controlling the collimation and rotation of hydrom…

We review recent observational and theoretical results on the relationship between circumstellar accretion disks and jets in young stellar objects. We then present a theoretical framework that interprets jets as accretion-powered,…

We consider the conditions under which a rotating magnetic object can produce a magnetically powered outflow in an initially unmagnetized medium stratified under gravity. 3D MHD simulations are presented in which the footpoints of…

Numerical simulations of outflows formed during the collapse of 100 M_sun cloud cores are presented. We derive a generalised criterion from MHD wind theory to analyse the launching mechanism of these outflows. The criterion is successfully…

In this paper, we propose a general method for perturtative solutions to Blandford-Znajek mechanism. Instead of solving the nonlinear Grad-Shafranov equation directly, we introduce an alternative way to determine relevant physical…

Using long-duration general relativistic magnetohydrodynamic simulations of radiatively inefficient accretion discs, the energy, momentum and mass outflow rates from such systems are estimated. Outflows occur via two fairly distinct modes:…

We present results of the first ever three-dimensional (3D) magnetohydrodynamic (MHD) simulations of the accretion-ejection structure. We investigate the 3D evolution of jets launched symmetrically from single stars but also jets from…

We review advances in the theoretical and computational studies of disk winds, jets and outflows including: the connection between accretion and jets, the launch of jets from magnetized disks, the coupled evolution of jets and disks, the…

Protostellar jets and winds are probably driven magnetocentrifugally from the surface of accretion disks close to the central stellar objects. The exact launching conditions on the disk, such as the distributions of magnetic flux and mass…

The theory of jet emitting disks (JEDs) provides a mathematical framework for a self-consistent treatment of steady-state accretion and ejection. A large-scale vertical magnetic field threads the accretion disk where magnetic turbulence…

Semi-analytical models of disk outflows have successfully described magnetically-driven, self-confined super-Alfv\'enic jets from near Keplerian accretion disks. These Jet Emitting Disks are possible for high levels of disk magnetization…

The launching of magnetohydrodynamic outflows from accretion disks is considered. We formulate a model for the local vertical structure of a thin disk threaded by a poloidal magnetic field of dipolar symmetry. The model consists of an…

Recent surveys show that protoplanetary disks have lower levels of turbulence than expected based on their observed accretion rates. A viable solution to this is that magnetized disk winds dominate angular momentum transport. This has…

Cold steady-state disk wind theory from near Keplerian accretion disks requires a large scale magnetic field at near equipartition strength. However the minimum magnetization has never been tested. We investigate the time evolution of an…

We present 2.5-dimensional time-dependent simulations of nonrelativistic and nonradiative outflows from sinusoidally perturbed Keplerian accretion disks. A sinusoidal perturbation is introduced in the velocity of the gas ejected from the…

We study time-dependent relativistic jets under the influence of radiation field of the accretion disk. The accretion disk consists of an inner compact corona and an outer sub-Keplerian disk. The thermodynamics of the fluid is governed by a…

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,…

We present a detailed physical analysis of the jet launching mechanism of a circum-stellar disk that is located in a binary system. Applying 3D resistive MHD simulations, we investigate the local and global properties of the system, such as…

We discuss recent progress in understanding the launching of outflows/jets from the disc-magnetosphere boundary of slowly and rapidly rotating magnetized stars. In most of the discussed models the interior of the disc is assumed to have a…

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…

General relativistic numerical simulations of magnetized accretion flows around black holes show a disordered electromagnetic structure in the disk and corona and a highly relativistic, Poynting-dominated funnel jet in the polar regions.…