The Imprint of the Protoplanetary Disk in the Accretion of Super-Earth Envelopes

Abstract

Super-Earths are by far the most dominant type of exoplanet, yet their formation is still not well understood. In particular, planet formation models predict that many of them should have accreted enough gas to become gas giants. Here we examine the role of the protoplanetary disk in the cooling and contraction of the protoplanetary envelope. In particular, we investigate the effects of 1) the thermal state of the disk as set by the relative size of heating by accretion or irradiation, and whether its energy is transported by radiation or convection, and 2) advection of entropy into the outer envelope by disk flows that penetrate the Hill sphere, as found in 3D global simulations. We find that, at 5 and 1 AU, this flow at the level reported in the non-isothermal simulations where it penetrates only to ~ 0.3 times the Hill radius has little effect on the cooling rate since most of the envelope mass is concentrated close to the core, and far from the flow. On the other hand, at 0.1 AU, the envelope quickly becomes fully-radiative, nearly isothermal, and thus cannot cool down, stalling gas accretion. This effect is significantly more pronounced in convective disks, leading to envelope mass orders of magnitude lower. Entropy advection at 0.1 AU in either radiative or convective disks could therefore explain why super-Earths failed to undergo runaway accretion. These results highlight the importance of the conditions and energy transport in the protoplanetary disk for the accretion of planetary envelopes.

arXiv comment10 pages, 6 figures, accepted for publication in MNRAS

References in corpus (38)

• Spectral Energy Distributions of T Tauri Stars With Passive Circumstellar Disks
• Rapid planetesimal formation in turbulent circumstellar discs
• The false positive rate of Kepler and the occurrence of planets
• Using FU Orionis Outbursts to Constrain Self-Regulated Protostellar Disk Models
• Kepler planets: a tale of evaporation
• The evaporation valley in the Kepler planets
• Understanding the Mass-Radius Relation for Sub-Neptunes: Radius as a Proxy for Composition
• The Mass-Radius Relation for 65 Exoplanets Smaller than 4 Earth Radii
• Accretion Disks Around Young Objects. III. Grain Growth
• The Minimum-Mass Extrasolar Nebula: In-Situ Formation of Close-In Super-Earths
• Sculpting the Valley in the Radius Distribution of Small Exoplanets as a by-product of Planet Formation: The Core-Powered Mass-Loss Mechanism
• Evolution of protoplanetary disks: Constraints from DM Tauri and GM Aurigae
• Atmospheres of protoplanetary cores: critical mass for nucleated instability
• Weak Turbulence in the HD 163296 Protoplanetary Disk Revealed by ALMA CO Observations
• The structure of protoplanetary discs around evolving young stars
• Super-Earth Atmospheres: Self-Consistent Gas Accretion and Retention
• Breeding Super-Earths and Birthing Super-Puffs in Transitional Disks
• A Three-Dimensional View of Turbulence: Constraints on Turbulent Motions in the HD 163296 Protoplanetary Disk using DCO${}^{+}$
• Make Super-Earths, Not Jupiters: Accreting Nebular Gas onto Solid Cores at 0.1 AU and Beyond
• Analytical protostellar disk models 1: the effect of internal dissipation and surface irradiation on the structure of disks and the location of the snow line around Sun-like stars
• To Cool is to Accrete: Analytic Scalings for Nebular Accretion of Planetary Atmospheres
• Detection of an atmosphere around the super-Earth 55 Cancri e
• On the Minimum Core Mass for Giant Planet Formation at Wide Separations
• Hydrodynamics of Embedded Planets' First Atmospheres. II. A Rapid Recycling of Atmospheric Gas
• Reduced gas accretion on super-Earths and ice giants
• Global Models of Planet Formation and Evolution
• An Atmospheric Structure Equation for Grain Growth
• Convective cooling and fragmentation of gravitationally unstable disks
• Uranus and Neptune: Origin, Evolution and Internal Structure
• Superabundance of Exoplanet Sub-Neptunes Explained by Fugacity Crisis
• Thermal Structure and Radius Evolution of Irradiated Gas Giant Planets
• Hydrodynamics of Embedded Planets' First Atmospheres. I. A Centrifugal Growth Barrier for 2D Flows
• Suppression of atmospheric recycling of planets embedded in a protoplanetary disc by buoyancy barrier
• Mapping the Conditions for Hydrodynamic Instability on Steady State Accretion Models of Protoplanetary Disks
• Circumplanetary Disk Dynamics in the Isothermal and Adiabatic Limits
• The Formation of Uranus & Neptune: Challenges and Implications For Intermediate-Mass Exoplanets
• On the angular momentum transport due to vertical convection in accretion discs
• Pebble dynamics and accretion onto rocky planets. I. Adiabatic and convective models

Cited by in corpus (26)

• The New Generation Planetary Population Synthesis (NGPPS). I. Bern global model of planet formation and evolution, model tests, and emerging planetary systems
• Primordial Radius Gap and Potentially Broad Core Mass Distributions of Super-Earths and Sub-Neptunes
• How planets grow by pebble accretion. III. Emergence of an interior composition gradient
• Creating the Radius Gap without Mass Loss
• Tidal Inflation Reconciles Low-Density Sub-Saturns with Core Accretion
• One year of AU Mic with HARPS: I -- measuring the masses of the two transiting planets
• Steady State by Recycling prevents Premature Collapse of Protoplanetary Atmospheres
• The Preservation of Super Earths and the Emergence of Gas Giants after Their Progenitor Cores have Entered the Pebble Isolation Phase
• Accretion of Gas Giants Constrained by the Tidal Barrier
• N-body simulations of planet formation via pebble accretion II. How various giant planets form
• Global 3D Radiation Hydrodynamic Simulations of Proto-Jupiter's Convective Envelope
• Recycling of the first atmospheres of embedded planets: Dependence on core mass and optical depth
• Retention of Long-Period Gas Giant Planets: Type II Migration Revisited
• Revising the Giant Planet Mass-Metallicity Relation: Deciphering the Formation Sequence of Giant Planets
• Dust Accumulation near the Magnetospheric Truncation of Protoplanetary Discs around T Tauri Stars
• Exoplanet atmosphere evolution: emulation with neural networks
• Unveiling the Planet Population at Birth
• Directly Detecting the Envelopes of Low-mass Planets Embedded In Protoplanetary Discs and The Case For TW Hydrae
• Dust processing in protoplanetary envelopes as the origin of hot minerals in comets
• Separated twins or just siblings? A multi-planet system around an M dwarf including a cool sub-Neptune
• Constraining protoplanetary disks with exoplanetary dynamics: Kepler-419 as an example
• The Critical Core Mass of Rotating Planets
• Effects of Self-gravity on Mass-loss of the Post-impact Super-Earths
• Ohmic dissipation during the formation of super-Earth
• In situ formation of super-Earth/sub-Neptune driven by the planetary rotation
• The effect of late giant collisions on the atmospheres of protoplanets and the formation of cold sub-Saturns