Accretion of Uranus and Neptune from inward-migrating planetary embryos blocked by Jupiter and Saturn

Abstract

Reproducing Uranus and Neptune remains a challenge for simulations of solar system formation. The ice giants' peculiar obliquities suggest that they both suffered giant collisions during their formation. Thus, there must have been an epoch of accretion dominated by collisions among large planetary embryos in the primordial outer solar system. We test this idea using N-body numerical simulations including the effects of a gaseous protoplanetary disk. One strong constraint is that the masses of the ice giants are very similar -- the Neptune/Uranus mass ratio is $\sim 1.18$. We show that similar-size ice giants do indeed form by collisions between planetary embryos beyond Saturn. The fraction of successful simulations varies depending on the initial number of planetary embryos in the system, their individual and total masses. Similar-sized ice giants are consistently reproduced in simulations starting with 5-10 planetary embryos with initial masses of $\sim$3-6 ${\mathrm{M}}_{\oplus }$. We conclude that accretion from a population of planetary embryos is a plausible scenario for the origin of Uranus and Neptune.

Accepted for publication in A&A

References in corpus (28)

• Most 1.6 Earth-Radius Planets are not Rocky
• The Occurrence and Mass Distribution of Close-in Super-Earths, Neptunes, and Jupiters
• Formation of Hot Planets by a combination of planet scattering, tidal circularization, and Kozai mechanism
• Origin of the Structure of the Kuiper Belt during a Dynamical Instability in the Orbits of Uranus and Neptune
• Separating gas-giant and ice-giant planets by halting pebble accretion
• Dynamics of the giant planets of the solar system in the gaseous proto-planetary disk and relationship to the current orbital architecture
• Halting Type I planet migration in non-isothermal disks
• Water Delivery and Giant Impacts in the 'Grand Tack' Scenario
• Three-dimensional simulations of multiple protoplanets embedded in a protostellar disc
• On the formation of planetary systems via oligarchic growth in thermally evolving viscous discs
• Tidal Heating of Extra-Solar Planets
• A Statistical Reconstruction of the Planet Population Around Kepler Solar-Type Stars
• Type I planetary migration in a self-gravitating disk
• On disc protoplanet interactions in a non-barotropic disc with thermal diffusion
• Lunar and Terrestrial Planet Formation in the Grand Tack Scenario
• On the formation and migration of giant planets in circumbinary discs
• Gas giant planets as dynamical barriers to inward-migrating super-Earths
• Accretion of Terrestrial Planets from Oligarchs in a Turbulent Disk
• Influence of an inner disc on the orbital evolution of massive planets migrating in resonance
• Growing and moving low-mass planets in non-isothermal disks
• Outward migration of Jupiter and Saturn in 3:2 or 2:1 resonance in radiative disks: implications for the Grand Tack and Nice models
• The Grand Tack model: a critical review
• Building Giant-Planet Cores at a Planet Trap
• Terrestrial Planet Formation in the Presence of Migrating Super-earths
• Challenges in Forming the Solar System's Giant Planet Cores via Pebble Accretion
• Models of the Collisional Damping Scenario for Ice Giant Planets and Kuiper Belt Formatio
• Planet Traps and Planetary Cores: Origins of the Planet-Metallicity Correlation
• Migration and Growth of Protoplanetary Embryos II: Emergence of Proto-Gas-Giants Cores versus Super Earths' Progenitor

Cited by in corpus (54)

• Dynamical Evolution of the Early Solar System
• Origin of water in the inner Solar System: Planetesimals scattered inward during Jupiter and Saturn's rapid gas accretion
• Formation of planetary systems by pebble accretion and migration: Growth of gas giants
• Formation of TRAPPIST-1 and other compact systems
• Challenges in Planet Formation
• Origin and Evolution of Short-Period Comets
• The nature and origins of sub-Neptune size planets
• Planetesimal rings as the cause of the Solar System's planetary architecture
• The Natural History of 'Oumuamua
• How planetary growth outperforms migration
• Uranus and Neptune: Origin, Evolution and Internal Structure
• Dynamical evidence for an early giant planet instability
• The Formation of Jupiter's Diluted Core by a Giant Impact
• Including Dust Coagulation in Hydrodynamic Models of Protoplanetary Disks: Dust Evolution in the Vicinity of a Jupiter-mass Planet
• Constraining the giant planets' initial configuration from their evolution: implications for the timing of the planetary instability
• Two new free-floating or wide-orbit planets from microlensing
• The formation of mini-Neptunes
• The eccentricity distribution of giant planets and their relation to super-Earths in the pebble accretion scenario
• The Asteroid Belt as a Relic From a Chaotic Early Solar System
• Influence of the water content in protoplanetary discs on planet migration and formation
• The inclination of the planetary system relative to the solar equator may be explained by the presence of Planet 9
• Revisiting the pre-main-sequence evolution of stars II. Consequences of planet formation on stellar surface composition
• Born eccentric: constraints on Jupiter and Saturn's pre-instability orbits
• The effect of a strong pressure bump in the Sun's natal disk: Terrestrial planet formation via planetesimal accretion rather than pebble accretion
• Tilting Ice Giants with a Spin-Orbit Resonance
• Making Planet Nine: A Scattered Giant in the Outer Solar System
• Did Jupiter's core form in the innermost parts of the Sun's protoplanetary disk?
• Kepler-167e as a Probe of the Formation Histories of Cold Giants with Inner Super-Earths
• Uranus and Neptune are key to understand planets with hydrogen atmospheres
• Formation of Terrestrial Planets
• Origin and dynamical evolution of the asteroid belt
• Key Atmospheric Signatures for Identifying the Source Reservoirs of Volatiles in Uranus and Neptune
• Tilting Uranus via the migration of an ancient satellite
• Dynamical origin of the Dwarf Planet Ceres
• Co-accretion + giant impact origin of the Uranus system: Tilting Impact
• Infrared Spectroscopy of HR 4796A's Bright Outer Cometary Ring + Tenuous Inner Hot Dust Cloud
• Could Uranus and Neptune form by collisions of planetary embryos?
• Predicting the water content of interstellar objects from galactic star formation histories
• On the Formation of Super-Earths with Implications for the Solar System
• Circularizing Planet Nine through dynamical friction with an extended, cold planetesimal belt
• Terrestrial planet and asteroid belt formation by Jupiter-Saturn chaotic excitation
• Late Accretion of Ceres-like Asteroids and Their Implantation into the Outer Main Belt
• Limits on the number of primordial Scattered Disk objects at Pluto mass and higher from the absence of their dynamical signatures on the present day trans-Neptunian Populations
• The GAPS Programme at TNG -- XXIV. An eccentric Neptune-mass planet near the inner edge of the BD-11 4672 habitable zone
• Observational constraints on the formation and evolution of Neptune-class exoplanets
• Dynamics of multiple protoplanets embedded in gas/pebble disks and its dependence on $\Sigma$ and $\nu$ parameters
• An early giant planet instability recorded in asteroidal meteorites
• Tilting Uranus via Secular Spin-Orbit Resonance with Planet 9
• A Wide Orbit Exoplanet OGLE-2012-BLG-0838Lb
• Very-wide-orbit planets from dynamical instabilities during the stellar birth cluster phase
• The late formation of chondrites as a consequence of Jupiter-induced gaps and rings
• Aero-Resonant Migration
• Reassessing planetary composition: Evidence of rock-dominated envelopes in Uranus and Neptune
• Shaken, not stirred: inefficient mixing of CM- and CI-like materials