Pushing planets into an inner cavity by a resonant chain

Context. The orbital distribution of exoplanets indicates an accumulation super-Earth sized planets close to their host stars in compact systems. When inward disc-driven migration scenario is assumed for formation, these could have been stopped and might parked at inner edge the disc, or be pushed through disc cavity by a resonant chain. This topic has not properly extensively studied. Using numerical simulations, we investigate possibility that chain can into outer planets. We performed hydrodynamical N-body simulations planetary systems embedded nascent disc. was represented two different ways, resembling either dead zone (DZ) boundary (IB). main difference lies steepness surface density profile. innermost planet always mass 10 M Earth , with additional equal higher mass. A steeper profile able stop more efficiently than shallower final configurations our DZ models are usually tighter IB counterparts, therefore prone instability. derive analytical expressions stopping conditions based on power equilibrium, show eccentricities result from torque equilibrium. For thinner discs, found, first time, clear signs over-stable librations leading very also found popular may overestimate number cavity.