Related papers: Diffusive Migration of Low-Mass Proto-planets in T…
Migration of protoplanets in their gaseous host disks may be largely responsible for the observed orbital distribution of extrasolar planets. Recent simulations have shown that the magnetorotational turbulence thought to drive accretion in…
(Abridged).We present the results of MHD simulations of low mass protoplanets interacting with turbulent disks. We calculate the orbital evolution of `planetesimals' and protoplanets with masses in the range 0 < m_p < 30 M_Earth.…
This paper presents a generalized treatment of Type I planetary migration in the presence of stochastic perturbations. In many planet-forming disks, the Type I migration mechanism, driven by asymmetric torques, acts on a short time scale…
The known exoplanet population displays a great diversity of orbital architectures, and explaining the origin of this is a major challenge for planet formation theories. The gravitational interaction between young planets and their…
Planet migration within inner protoplanetary disks significantly influences exoplanet architectures. We investigate various migration mechanisms for young planets close to young stars. To quantify the stochastic migration driven by…
Recent surveys show that protoplanetary disks have lower levels of turbulence than expected based on their observed accretion rates. A viable solution to this is that magnetized disk winds dominate angular momentum transport. This has…
We present detailed estimates of ''type-I'' migration rates for low-mass proto-planets embedded in steady-state T-Tauri alpha-disks, based on Lindblad torque calculations ignoring feedback on the disk. Differences in migration rates for…
Gravitational torques between a planet and gas in the protoplanetary disk result in orbital migration of the planet, and are likely to play an important role in the formation and early evolution of planetary systems. For masses comparable…
By performing global hydrodynamical simulations of accretion discs with driven turbulence models, we demonstrate that elevated levels of turbulence induce highly stochastic migration torques on low-mass companions embedded in these discs.…
Disc-driven planet migration is integral to the formation of planetary systems. In standard, gas-dominated protoplanetary discs, low-mass planets or planetary cores undergo rapid inwards migration and are lost to the central star. However,…
Low-mass planets are known to undergo Type I migration and this process must have played a key role during the evolution of planetary systems. Analytical formulae for the disc torque have been derived assuming that the planet evolves on a…
In order to reproduce the statistical properties of the observed exoplanets, population synthesis models have shown that the migration of protoplanets should be significantly slowed down, and that processes stalling migration should be at…
Due to the gravitational influence of density fluctuations driven by magneto-rotational instability in the gas disk, planetesimals and protoplanets undergo diffusive radial migration as well as changes in other orbital properties. The…
This paper continues previous work on the effects of turbulence on mean motion resonances in extrasolar planetary systems. Turbulence is expected to arise in the disks that form planets, and these fluctuations act to compromise resonant…
As planets form and grow within gaseous protoplanetary disks, the mutual gravitational interaction between the disk and planet leads to the exchange of angular momentum, and migration of the planet. We review current understanding of…
In low-mass disks, turbulent torques are probably the most important way of redistributing angular momentum. Here we present the theory of turbulent accretion disks. We show the molecular viscosity is far too small to account for the…
We quantify the utility of large radial velocity surveys for constraining theoretical models of Type II migration and protoplanetary disk physics. We describe a theoretical model for the expected radial distribution of extrasolar planets…
This paper considers the effects of turbulence on mean motion resonances in extrasolar planetary systems and predicts that systems rarely survive in a resonant configuration. A growing number of systems are reported to be in resonance,…
Protoplanetary disks are likely to be threaded by a weak net flux of vertical magnetic field that is a remnant of the much larger fluxes present in molecular cloud cores. If this flux is approximately conserved its dynamical importance will…
We review results about protoplanetary disk models, protoplanet migration and formation of giant planets with migrating cores. We first model the protoplanetary nebula as an \alpha-accretion disk and present steady state calculations for…