Migration of massive planets

Massive planets should undergo so-called type II migration in which there is a negligible flow of gas between the regions of disc interior/exterior to the planet, yielding a planet speed comparable to that of the gas. However, two recent works using different numerical schemes have demonstrated that there is in fact a significant flow of material between interior and exterior discs even when using parameters that had previously been believed to be firmly in the ‘type II’ regime. Consequently, in these simulations, the planet migration speed is unrelated to the viscous flow speed of the disc. This suggests that the most rapid migration occurs in an initial transient and that the migration rate declines later in the simulation, arguably as a result of the diminished flow across the gap at later stages.

Exploration of this issue requires long timescale simulations with duration of order the viscous time (~105 orbits). We will use the remapping scheme in the FARGO code, that is well equipped to tackle this problem.

Our goals are:

  1. Study the migration rates of massive planets from hydrodynamical simulations. For the first time we would evolve these simulations for a viscous timescale of the disc.
  2. Incorporate in planet formation simulations the newly derived migration rates to study how this affects the final locations of giant planets after the dispersal of the proto-planetary disc.