Protostellar Jets Driven by a Disorganized Magnetic Field
نویسنده
چکیده
We have proposed a viscoelastic model of the Maxwell stresses due to the disorganized magnetic field in MRI-driven MHD turbulence. Viscoelastic fluids in the laboratory are known to produce jet-like structures under the action of a rotating sphere. Here we argue that a similar mechanism may help explain jets in protostellar systems. Such jets would be driven not by large-scale organized magnetic fields, but by the meanfield stresses of small-scale tangled magnetic fields.
منابع مشابه
Protostellar Jet and Outflow in the Collapsing Cloud Core
Using three-dimensional resistive MHD nested grid simulations, we investigate the driving mechanism of outflows and jets in star formation process. Starting with a Bonnor-Ebert isothermal cloud rotating in a uniform magnetic field, we calculated cloud evolution from the molecular cloud core (nc = 10 4 cm, r = 4.6×10 AU) to the stellar core (nc = 10 22 cm, r ∼ 1R⊙), where nc and r denote the cen...
متن کاملMagnetic Fields in Astrophysical Jets: From Launch to Termination
Long-lived, stable jets are observed in a wide variety of systems, from protostars, through Galactic compact objects to active galactic nuclei (AGN). Magnetic fields play a central role in launching, accelerating, and collimating the jets through various media. The termination of jets in molecular clouds or the interstellar medium deposits enormous amounts of mechanical energy and momentum, and...
متن کاملDecay of the toroidal field in magnetically driven jets
A 3D simulation of a non-relativistic, magnetically driven jet propagating in a stratified atmosphere is presented, covering about three decades in distance and two decades in sideways expansion. The simulation captures the jet acceleration through the critical surfaces and the development of (kink-)instabilities driven by the free energy in the toroidal magnetic field component. The instabilit...
متن کاملThe First Jet in the Universe: Protostellar Jets from the First Stars
The protostellar jets driven by the formation of the first stars are studied by using three-dimensional magnetohydrodynamical (MHD) nested grid simulations. Starting from a slowly rotating spherical cloud of 5.1× 10M⊙ permeated by a uniform magnetic field, we follow the evolution from the central number density nc = 10 3 cm (where the radius of the object r = 6.6 pc) to nc ≃ 10 23 cm ( r ≃ 1R⊙)...
متن کاملOutflows and Jets from Collapsing Magnetized Cloud Cores
Star formation is usually accompanied by outflow phenomena. There is strong evidence that these outflows and jets are launched from the protostellar disk by magneto-rotational processes. Here, we report on our three dimensional, adaptive mesh, magneto-hydrodynamic simulations of collapsing, rotating, magnetized Bonnor-Ebert-Spheres whose properties are taken directly from observations. In contr...
متن کامل