Mario Flock (CEA) Thursday November 27th - 11am IPAG Seminar Room - IPAG
In this seminar I present recent results regarding the dynamics and thermodynamics of gas and dust in magnetized and turbulent protoplanetary disks.
I will focus on the inner and outer regions of protoplanetary disks. To study the inner disk regions, we developed a radiative transfer module, based on the flux-limited diffusion approximation that includes frequency dependent irradiation and dust opacities. We present results of the first global 3D radiation magneto-hydrodynamic simulations of a stratified protoplanetary disk. The present work demonstrates for the first time that global radiation magneto–hydrodynamic simulations of turbulent protoplanetary disks are feasible with current computational facilities. This opens up the windows to a wide range of studies of the dynamics of protoplanetary disks, especially their inner parts for which there are significant observational constraints.
In the second part I focus on the outer protoplanetary disk regions. Recent ALMA observations of young stars revealed distinct asymmetries in the dust continuum emission by their embedded disks. In our work we study the large scale structures, evocated by the magneto-rotational instability in the outer regions of protoplanetary disk. We combine the results of non-ideal global 3D MHD stratified simulations with post-processing radiation transfer to generate synthetic maps and predictions for the Atacama Large Millimeter Array. Our model develops a large zonal flow at the outer edge of the dead-zone which is sustained. This structure is characterized by a combination of gap followed by a jump in surface density. Inside the jump, which is nearly a ring structure, we observe the generation of vortices by the Rossby-Wave instability. Our models show a new possibility to generate density gaps and enhancements which leads to vortex formation in the outer regions of protoplanetary disks.
Dans la même rubrique :