Pathways to Forming (Near) Resonant Planets In Situ In Context With a Giant Outer Planet

We investigate the dynamical histories of planets forming in situ within about 1 AU of the host star that form resonant chains with and without the presence of an outer giant planet. Dynamical simulations of the giant impact phase of planet formation were performed, including a dissipative residual gas disk and a post-disk dispersal, subsequent dynamical evolution phase. When a giant planet is not present, planets lock into resonance during the disk phase in a fraction of systems. These resonances persist post-disk dispersal, with planets avoiding subsequent giant impacts that could disrupt the resonances. Using the same initial conditions for the inner planets, we compare planet merger histories and resulting system architectures when an outer massive planet is present several AU exterior to the inner planet region. We place the simulated system outcomes in context with the observed portions of systems from the Kepler mission, including systems containing known resonant chains such as Kepler-223 and Kepler-80.