On the orbital evolution of low mass protoplanets in turbulent, magnetised disks

摘要: We present the results of MHD simulations low mass protoplanets interacting with turbulent, magnetised protostellar disks. calculate orbital evolution planetesimals and masses in range 0 ≤ m p < 30 M ○+ . The disk models are cylindrical toroidal net-flux magnetic fields, having aspect ratio H/r = 0.07 effective viscous stress parameter α 5 × 10 -3 A significant result is that planetesimals, all considered, undergo stochastic migration due to gravitational interaction turbulent density fluctuations disk. For simulation run times currently feasible (covering between 100-150 planet orbits), dominates over type I for many models. Fourier analysis torques experienced by indicates torque contain components power whose time scales variation similar times, These long term part explain dominance models, may provide a powerful means counteracting effects acting on some planets effect superposing appropriate laminar disks was examined. This predicts greater degree inward should occur than observed simulations. be first hint modified disk, but not conclusive this matter. turbulence found source eccentricity driving, attaining eccentricities 0.02 e 0.14 during shows strong dependence protoplanet mass. Protoplanets 1 attained 0.08. Those reached 0.03. trend basic agreement model which growth arises because forcing, damping occurs through material at coorhilal Lindblad resonances. theory formation. Stochastic preventing least planetary cores from migrating into central star before they become gas giants. he enhanced hy isolation planetesimal accretion. excitation turbulence, however, act reduce rates runaway oligarchic stages, cause collisions destructive rather accumulative.