Séminaire Exoplanètes / |
| « Outflows from turbulent accretion disks » |
|
Sébastien Fromang |
| MHD turbulence powered by the magnetorotational instability is believed to be the main physical mechanism responsible for angular momentum transport in accretion disks. Despite twenty years of detailed studies of its properties, the saturation amplitude of the turbulence is still not well constrained. In particular, the most natural situation, a mean vertical magnetic field threading an accretion disk, has only been extensively studied in homogeneous situations thought to be relevant at the disk midplane. Such a configuration precludes a detailed study of the interplay between MHD turbulence and the jets that are observed to be launched by accretion disks. I will show the results of recent numerical simulations that investigate that interaction for the first time. I will make connexion with classical disk wind theories, constrain the relative importance between turbulent and outflow angular momentum transport and highlight the limits of the approach currently used. Finally, the special case of protoplanetary disks will be discussed based on new results that recently appeared in the literature. |
|
mercredi 24 avril 2013 - 14:30 Salle Daniel Chalonge Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |