Rapid Formation of Jupiter and Wide-Orbit Exoplanets in Disks with Pressure Bumps

Abstract

The formation of gas-giant planets within the lifetime of a protoplanetary disk is challenging especially far from a star. A promising model for the rapid formation of giant-planet cores is pebble accretion in which gas drag during encounters leads to high accretion rates. Most models of pebble accretion consider disks with a monotonic, radial pressure profile. This causes a continuous inward flux of pebbles and inefficient growth. Here we examine planet formation in a disk with multiple, intrinsic pressure bumps. In the outer disk, pebbles become trapped near these bumps allowing rapid growth under suitable conditions. In the inner disk, pebble traps may not exist because the inward gas advection velocity is too high. Pebbles here are rapidly removed. In the outer disk, growth is very sensitive to the initial planet mass and the strength of turbulence. This is because turbulent density fluctuations raise planetary eccentricities, increasing the planet-pebble relative velocity. Planetary seeds above a distance-dependent critical mass grow to a Jupiter mass in 0.5--3 million years out to at least 60 AU in a 0.03 solar-mass disk. Smaller bodies remain near their initial mass, leading to a sharp dichotomy in growth outcomes. For turbulent alpha = 1e-4, the critical masses are 1e-4 and 1e-3 Earth masses at 9 and 75 AU, respectively. Pressure bumps in disks may explain the large mass difference between the giant planets and Kuiper belt objects, and also the existence of wide-orbit planets in some systems.

Accepted for publication in The Astrophysical Journal

References in corpus (21)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Particle Stirring in Turbulent Gas Disks: Including Orbital Oscillations
• Planet formation around stars of various masses: The snow line and the frequency of giant planets
• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU
• Two accreting protoplanets around the young star PDS 70
• Separating gas-giant and ice-giant planets by halting pebble accretion
• Grain Retention and Formation of Planetesimals near the Snow Line in MRI-driven Turbulent Protoplanetary Disks
• On the Location of the Snow Line in a Protoplanetary Disk
• Initial mass function of planetesimals formed by the streaming instability
• On the formation of planetary systems via oligarchic growth in thermally evolving viscous discs
• Accretion and destruction of planetesimals in turbulent disks
• The population of long-period transiting exoplanets
• Planet formation by pebble accretion in ringed disks
• Convergence of the critical cooling rate for protoplanetary disk fragmentation achieved; the key role of numerical dissipation of angular momentum
• Giant planet formation at the pressure maxima of protoplanetary disks II. A hybrid accretion scenario
• Challenges in Forming the Solar System's Giant Planet Cores via Pebble Accretion
• Planet Candidates from K2 Campaigns 5-8 and Follow-Up Optical Spectroscopy
• Exploring the conditions for forming cold gas giants through planetesimal accretion
• A new and simple prescription for planet orbital migration and eccentricity damping by planet-disc interactions based on dynamical friction
• The End of Runaway: How Gap Opening Limits the Final Masses of Gas Giants
• K2-HERMES II. Planet-candidate properties from K2 Campaigns 1-13

Cited by in corpus (17)

• Efficient planet formation by pebble accretion in ALMA rings
• Rapid Formation of Massive Planetary Cores in a Pressure Bump
• From Pebbles and Planetesimals to Planets and Dust: the Protoplanetary Disk--Debris Disk Connection
• Sequential giant planet formation initiated by disc substructure
• The role of the drag force in the gravitational stability of dusty planet-forming disc -- II. Numerical simulations
• Quantifying the Impact of the Dust Torque on the Migration of Low-mass Planets
• Formation of wide-orbit giant planets in protoplanetary disks with a decreasing pebble flux
• Self-consistent ring model in protoplanetary disks: temperature dips and substructure formation
• On the suppression of giant planet formation around low-mass stars in clustered environments
• Three-dimensional transport of solids in a protoplanetary disk containing a growing giant planet
• Growth after the streaming instability: The radial distance dependence of the planetary growth
• Orbital Migration of Protoplanets in a Marginally Gravitationally Unstable Disk. II. Migration, Merging, and Ejection
• Planetesimal and planet formation in transient dust traps
• Flux-Limited Diffusion Approximation Models of Giant Planet Formation by Disk Instability. II. Quadrupled Spatial Resolution
• Accreting luminous low-mass planets escape from migration traps at pressure bumps
• Formation of Multiple Dynamical Classes in the Kuiper Belt via Disk Dissipation
• A tension between dust and gas radii: the role of substructures and external photoevaporation in protoplanetary disks