Multiple-Planet Scattering and the Origin of Hot Jupiters

摘要: Exoplanets show a pile-up of Jupiter-size planets in orbits with 3-day period. A fraction these hot Jupiters have retrograde respect to the parent star's rotation. To explain observations we performed series numerical integrations planet scattering followed by tidal circularization. We considered planetary systems having 3 and 4 initially. found that standard Kozai migration is an inefficient mechanism for formation Jupiters. Our results two distinct populations The inner population semimajor axis 1 Gyr. distribution Population II fits nicely observed pile-up. The inclination outer depends on number initial 4-planet case showed larger proportion (up 10%), wider spread values. As later roughly agrees observations, this may suggest were originally rich planets, some which ejected. In broad perspective, our work therefore hints unexpected link between recently discovered free floating planets.