The Impact of Self-Gravity on Planet and Disc Evolution in the Kepler-16, 34 and 35 Circumbinary Systems
Résumé
We present results from 2D hydrodynamic simulations of circumbinary discs, and the evolution of embedded planetary cores, with application to the Kepler-16, 34 and 35 systems. These cover a range of binary mass and orbital properties, but all share a common planetary architecture, with the planet lying close to the critical stability limit. This position also lies in the vicinity of the theoretical disc cavity edge created through tidal interaction with the host binary. Understanding what affects the evolution of the circumbinary disc is vital to explaining the final orbital configuration; we have undertaken simulations examining the role of the inner disc boundary conditions as well as the impact of self-gravity. Planetary cores are inserted into these evolved discs, simulating cores that have formed in the outer disc and migrated inwards, with the aim of recreating the observed Kepler circumbinary planetary systems. The choice of inner boundary condition has a clear impact on the disc structure and the evolution of protoplanetary cores. We find significant structure in massive self-gravitating discs, suggesting that younger circumbinary discs could be hostile environments for planetary formation and migration, out to larger radii than previously found.