General Physics Seminar 16 December 2004


Instabilities in magnetized accretion disks

Eric van der Swaluw
FOM-Institute for Plasma Physics Rijnhuizen


Accretion disks are astrophysical objects present around a variety of stellar objects: from young (proto-)stars to massive black holes. Via an accretion disk, the material is allowed to be transported towards the central object, thereby releasing part of its gravitational energy. Part of the gravitational energy released, is emitted over a wide range of frequencies, which in its turn is being observed by modern observational facilities. In order to have an efficient accretion process, angular momentum has to be transported outwards in the disk. This angular momentum transport is driven by instabilities present in a magnetized disk. We have used the expertise present at FOM in magnetohydrodynamic spectroscopy for laboratory plasma configurations, in order to investigate the instabilities present in these astrophysical systems.