Wednesday 04 Mar 2015: Seminar: Thermodynamics or the dead zone inner edge in protoplanetary disks ***11am***
Dr Julien Faure - Queen Mary, London
Physics, 4th floor 11:00-12:00
In protoplanetary disks, the inner boundary between an MRI active and inactive region has recently been proposed as a major ingredient of planet formation/evolution theory. A set of numerical simulations has indeed shown that the formation of a vortex, known to promote planet formation, is a natural consequence of the disk dynamics at that location. However, such models have so far considered only the case of an isothermal equation of state, while the complex thermodynamics is at the heart of how this region works.
Using the Godunov code Ramses, we have performed 3D global numerical simulations of protoplanetary disks that relax the isothermal hypothesis. We find that, at the interface, the disk thermodynamics and the turbulent dynamics are intimately entwined, because of the importance of turbulent dissipation and thermal ionisation. This interaction drives an unexpected new phenomenon that may compromise the formation of planetesimals at the inner edge: Vortices forming at the interface follow a cycle of formation-migration-destruction.