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Mardi 02 avril 2013-14:00

The Rossby wave instability : 3D study and astrophysical implications

Heloise Meheut (Service d’astrophysique, CEA Saclay)

par Bertrand Georgeot - 2 avril 2013

The universe is a fantastic laboratory to test theoretical studies of extreme environments. We are here interested in flows exposed to very strong differential rotation with Reynolds number as high as 10^18, and we consider astrophysical accretion disks (e.g. disks surrounding black holes or very young stars) to study the Rossby wave instability (RWI). This instability is characterized by the coupling of two vorticity waves (Rossby waves) that can form vortices despite the destructive impact of differential rotation. Such vortices have strong astrophysical consequences and may be detected in protoplanetary disks in the next few years.

In this talk, I present the linear study of the RWI in 3D in the WKB approximation and show how this new approach where the vertical stratification is considered, modify the understanding of the 3D structure of waves. Then, I present non-linear high-performance numerical simulations of this instability. These are in agreement with the linear approach, and exhibit the long term evolution of the 3D vortices. Finally, the consequences for planet formation theory are discussed, as well as the possible observational confirmations.

Post-scriptum :

contact : Pierre-Henri Chavanis