Planets in turbulent disks

Abstract

Accretion disks are the birthplace of planets, the properties and evolution of which are highly sensitive to the thermo- and hydrodynamics of the gaseous disk that they are embedded in during their growth. Understanding the processes that define the structure of gas in the disk and the mechanisms that drive accretion is essential to modeling planet-disk interaction with numerical simulations.

Over the course of this project, we look into various aspects of protoplanetary disk dynamics. We examine the impact of different radiative effects on planet-disk interaction, explore the behavior of planet-generated vortices, and investigate the physical properties of the vertical shear instability (VSI) as an accretion-driving mechanism in protoplanetary disks. To that end, we perform numerical hydrodynamics simulations of accretion disks with and without embedded planets, using a wide variety of physical and numerical parameters and various post-processing techniques in order to validate, compare, and understand the results of our models.

We find that the equation of state is of key importance to modeling the formation of rings and gaps by planets, and highlight the impact of different radiative mechanisms on the density and temperature profile of the disk as well as on the lifetime of vortices generated by such planets. Regarding the VSI, we show that it is a competitive candidate in interpreting accretion in observations of protoplanetary disks and identify conditions for which a planet can coexist with or suppress the turbulent stress that this mechanism can generate. Finally, we find that the stress generated by vortices and spiral arms, while conducive to accretion, can weaken or quench the VSI and therefore limit its vertical mixing capacity.

Our results outline that appropriate treatment of radiative effects is crucial in numerical models of planet-disk interaction. Our work also suggests that observing VSI signatures in the presence of massive planets is unlikely, but perhaps possible in the future and during earlier stages of planet formation.