Formation of Hot Planets by a Combination of Planet Scattering, Tidal Circularization, and the Kozai Mechanism

摘要: We have investigated the formation of close-in extrasolar giant planets through a coupling effect mutual scattering, Kozai mechanism, and tidal circularization, by orbital integrations. Close-in gas giants would been originally formed at several AU beyond ice lines in protoplanetary disks migrated close to their host stars. Although type II migration due planet-disk interactions may be major channel for migration, we show that this scattering process also give nonnegligible contribution. carried out integrations three with Jupiter mass, directly including circularization. found about 30% runs are formed, which is much higher than suggested previous studies. Three-planet orbit crossing usually results ejection one or two planets. Tidal circularization often occurs during three-planet crossing, but studies monitored only final stage after ejection, significantly underestimating probability. mechanism outer responsible During excitation repeated eccentricity increased secularly values enough unity transform inner planet planet. Since moderate can retain planet, account observed eccentricities without nearby secondary these remain broad range inclinations (even retrograde ones), contribution clarified more observations Rossiter-McLaughlin effects transiting