Magnetically driven accretion in protoplanetary discs
نویسندگان
چکیده
منابع مشابه
Episodic accretion in magnetically layered protoplanetary discs
We study protoplanetary disc evolution assuming that angular momentum transport is driven by gravitational instability at large radii, and magnetohydrodynamic (MHD) turbulence in the hot inner regions. At radii of the order of 1 AU such discs develop a magnetically layered structure, with accretion occurring in an ionized surface layer overlying quiescent gas that is too cool to sustain MHD tur...
متن کاملMagnetically-driven jets from Keplerian accretion discs
Non-relativistic, magnetically-driven jets are constructed by taking self-consistently into account the feedback on the underlying accretion disc. It is shown that such jets are mostly described by the ejection index ξ = d ln Ṁa/d ln r, which is a local measure of the disc ejection efficiency. This parameter is found to lie in a very narrow range, due to constraints imposed by both the disc ver...
متن کاملStability and heating of magnetically driven jets from Keplerian accretion discs
We have performed 3-D numerical magnetohydrodynamic (MHD) jet experiments to study the instabilities associated with strongly toroidal magnetic fields. In contemporary jet theories, a highly wound up magnetic field is a crucial ingredient for collimation of the flow. If such magnetic configurations are as unstable as found in the laboratory and by analytical estimates, our understanding of MHD ...
متن کاملMagnetized accretion-ejection structures IV. Magnetically-driven jets from resistive, viscous, Keplerian discs
We present steady-state calculations of self-similar magnetized accretion discs driving cold, adiabatic, non-relativistic jets. For the first time, both the magnetic torque due to the jets and a turbulent “viscous” torque are taken into account. This latter torque allows a dissipation of the accretion power as radiation at the disc surfaces, while the former predominantly provides jets with pow...
متن کاملMagnetorotational instability in protoplanetary discs
We investigate the linear growth and vertical structure of the magnetorotational instability (MRI) in weakly ionised, stratified accretion discs. The magnetic field is initially vertical and dust grains are assumed to have settled towards the midplane, so charges are carried by electrons and ions only. Solutions are obtained at representative radial locations from the central protostar for diff...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 2015
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/stv2070