The Growth of Protoplanets via the Accretion of Small Bodies in Disks Perturbed by the Planetary Gravity

Abstract

Planets grow via the collisional accretion of small bodies in a protoplanetary disk. Such small bodies feel strong gas drag and their orbits are significantly affected by the gas flow and atmospheric structure around the planet. We investigate the gas flow in the protoplanetary disk perturbed by the gravity of the planet by three-dimensional hydrodynamic simulation. We then calculate the orbital evolutions of particles in the gas structure obtained from the hydrodynamic simulation. Based on the orbital calculations, we obtain the collision rate between the planet and centimeter to kilometer sized particles. Our results show that meter-sized or larger particles effectively collide with the planet due to the atmospheric gas drag, which significantly enhances the collision rate. On the other hand, the gas flow plays an important role for smaller particles. Finally, considering the effects of the atmosphere and gas flow, we derive the new analytic formula for the collision rate, which is in good agreement with our simulations. We estimate the growth timescale and accretion efficiency of drifting bodies for the formation of a gas-giant solid core using the formula. We find the accretion of sub-kilometer sized bodies achieve a short growth timescale (~0.005 Myr) and a high accretion efficiency (~1) for the core formation at 5 au in the minimum mass solar nebula model.

Accepted for publication in The Astrophysical Journal

References in corpus (14)

• Particle Stirring in Turbulent Gas Disks: Including Orbital Oscillations
• The Athena++ Adaptive Mesh Refinement Framework: Design and Magnetohydrodynamic Solvers
• Hydrodynamics of Embedded Planets' First Atmospheres. II. A Rapid Recycling of Atmospheric Gas
• Reduced gas accretion on super-Earths and ice giants
• Hydrodynamics of embedded planets' first atmospheres - III. The role of radiation transport for super-Earth planets
• Planet Formation with Migration
• Hydrodynamics of Embedded Planets' First Atmospheres. I. A Centrifugal Growth Barrier for 2D Flows
• Circumplanetary Disk Dynamics in the Isothermal and Adiabatic Limits
• Envelopes of embedded super-Earths II. Three-dimensional isothermal simulations
• Steady State by Recycling prevents Premature Collapse of Protoplanetary Atmospheres
• Gas flow around a planet embedded in a protoplanetary disc: the dependence on the planetary mass
• Influences of three-dimensional gas flow induced by protoplanets on pebble accretion --$\mathrm{I}$. shear regime
• Oscillatory migration of accreting protoplanets driven by a 3D distortion of the gas flow
• Influences of protoplanet-induced three-dimensional gas flow on pebble accretion $\mathrm{I}\mathrm{I}$. Headwind regime

Cited by in corpus (10)

• On the mass of gas giant planets: Is Saturn a failed gas giant?
• Rapid formation of Gas Giant Planets via Collisional Coagulation from Dust Grains to Planetary Cores
• An Analytical Theory for the Growth from Planetesimals to Planets by Polydisperse Pebble Accretion
• Heavy-element Accretion by Proto-Jupiter in a Massive Planetesimal Disk, Revisited
• Dust ring and gap formation by gas flow induced by low-mass planets embedded in protoplanetary disks $\mathrm{I}$. Steady-state model
• On the origin of transition disk cavities: Pebble-accreting protoplanets vs Super-Jupiters
• Thermal Processing of Solids Encountering a Young Jovian Core
• Accretion of aerodynamically large pebbles
• The influence of a static planetary atmosphere on spin transfer during pebble accretion
• Interior dynamics of envelopes around disk-embedded planets