Accretion of Terrestrial Planets from Oligarchs in a Turbulent Disk

Abstract

We have investigated the final accretion stage of terrestrial planets from Mars-mass protoplanets that formed through oligarchic growth in a disk comparable to the minimum mass solar nebula (MMSN), through N-body simulation including random torques exerted by disk turbulence due to Magneto-Rotational-Instability. For the torques, we used the semi-analytical formula developed by Laughlin et al.(2004). The damping of orbital eccentricities (in all runs) and type-I migration (in some runs) due to the tidal interactions with disk gas are also included. We found that the orbital eccentricities pumped up by the turbulent torques and associated random walks in semimajor axes tend to delay isolation of planets, resulting in more coagulation of planets than in the case without turbulence. The eccentricities are still damped after planets become isolated. As a result, the number of final planets decreases with increase in strength of the turbulence, while Earth-mass planets with small eccentricities are still formed. In the case of relatively strong turbulence, the number of final planets are 4-5 at 0.5-2AU, which is consistent with Solar system, for relatively wide range of disk surface density (~10^{-4}-10^{-2} times MMSN).

accepted for publication in Icarus; 19 pages, 8 figures, 1 table

References in corpus (2)

• Diffusive Migration of Low-Mass Proto-planets in Turbulent Disks
• Spitzer 24 micron Survey of Debris Disks in the Pleiades

Cited by in corpus (16)

• Building Terrestrial Planets
• Hot super-Earths and giant planet cores from different migration histories
• Accretion and destruction of planetesimals in turbulent disks
• Orbital Migration of Interacting Stellar Mass Black Holes in Disks around Supermassive Black Holes II. Spins and Incoming Objects
• 3D MHD Simulations of Planet Migration in Turbulent Stratified Disks
• Formation and accretion history of terrestrial planets from runaway growth through to late time: implications for orbital eccentricity
• Building Giant-Planet Cores at a Planet Trap
• The Demographics of Rocky Free-Floating Planets and their Detectability by WFIRST
• A new and simple prescription for planet orbital migration and eccentricity damping by planet-disc interactions based on dynamical friction
• Growing Mars fast: High-resolution GPU simulations of embryo formation
• Formation of terrestrial planets in disks evolving via disk winds and implications for the origin of the solar system's terrestrial planets
• Promoted Mass Growth of Multiple, Distant Giant Planets through Pebble Accretion and Planet-Planet Collision
• The Kepler-223 resonance holds information on turbulence during the gas disk phase
• Transit-Timing Variation Signature of Planet Migration: The Case of K2-24
• Mars' formation can constrain the primordial orbits of the gas giants
• The late formation of chondrites as a consequence of Jupiter-induced gaps and rings