Planetesimals in the Presence of Giant Planet Migration

We present N-body simulations illustrating how giant planet migration can significantly affect the conditions for the formation of interior terrestrial planets. A giant planet migrating through a swarm of planetesimals will scatter many of them onto very eccentric and inclined orbits, preventing them from playing any further role in additional planet formation. The magnitude of this excitation is strongly dependent on the mass and migration rate of the giant planet. We found that if planet migration occurs for low-mass planets (one-tenth of the mass of Jupiter) or proceeds very rapidly (10-3 AU yr-1), planetesimal swarms can dynamically cool via gas drag, collisions, and dynamical friction after the giant passes through. Other simulations produce a population of planetesimals on orbits with very high eccentricity and inclination, which may persist and become a signature of a previous migration event. In some cases further growth of terrestrial planets is possible, leading to our prediction of terrestrial planets existing on orbits outside of some hot Jupiters.