May 16
Abstract:
Accretion discs are observed around several astrophysical objects, from young stars to supermassive black holes in AGNs. To explain their luminosity and therefore their accretion rate, people rely on very simplified models of angular momentum transport and extraction, such as the alpha disc model. The magnetorotational instability is believed to be one of the mechanisms responsible for the angular momentum transport in discs. However, the saturation of this instability as well as its impact on large scale structures are still poorly understood.
During this talk, I will review some of the properties of the turbulence generated by the magnetorotational instability, and in particular its sensitivity to small scale physics. I will present a detailed spectral analysis of the energy cascade which could potentially explain some of theses properties and their implications for realistic astrophysical objects. Finally, if time permits, I will show some results on outflows produced by the magnetorotational instability. Comparisons with classical disc wind solutions as well as wind stability will also be discussed.