Vertical gas accretion impacts the carbon-to-oxygen ratio of gas giant atmospheres

Abstract

Recent theoretical, numerical, and observational work have suggested that when a growing planet opens a gap in its disk the flow of gas into the gap is dominated by gas falling vertically from a height of at least one gas scale height. Our primary objective is to include, for the first time, the chemical impact that accreting gas above the midplane will have on the resulting C/O. We compute the accretion of gas onto planetary cores beginning at different disk radii and track the chemical composition of the gas and small icy grains to predict the resulting carbon-to-oxygen ratio (C/O) in their atmospheres. In our model, all of the planets which began their evolution inward of 60 AU open a gap in the gas disk, and hence are chemically affected by the vertically accreting gas. Two important conclusions follow from this vertical flow: (1) more oxygen rich icy dust grains become available for accretion onto the planetary atmosphere. (2) The chemical composition of the gas dominates the final C/O of planets in the inner ($<$ 20 AU) part of the disk. This implies that with the launch of the James Webb Space Telescope we can trace the disk material that sets the chemical composition of exoplanetary atmospheres.

Accepted for publication in A&A

References in corpus (26)

• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• The Gemini Planet Imager Exoplanet Survey: Giant Planet and Brown Dwarf Demographics From 10-100 AU
• Toward a Deterministic Model of Planetary Formation V. Accumulation Near the Ice Line
• The imprint of exoplanet formation history on observable present-day spectra of hot Jupiters
• Exploring Exoplanet Populations with NASA's Kepler Mission
• Meridional flows in the disk around a young star
• Spitzer observations of the Orion OB1 association: disk census in the low mass stars
• Setting the volatile composition of (exo)planet-building material. Does chemical evolution in disk midplanes matter?
• Planet-forming material in a protoplanetary disc: the interplay between chemical evolution and pebble drift
• Reprocessing of Ices in Turbulent Protoplanetary Disks: Carbon and Nitrogen Chemistry
• Dynamical corotation torques on low-mass planets
• Composition of Early Planetary Atmospheres I: Connecting Disk Astrochemistry to the Formation of Planetary Atmospheres
• Hall-effect Mediated Magnetic Flux Transport in Protoplanetary Disks
• Connecting planet formation and astrochemistry: A main sequence for C/O in hot-exoplanetary atmospheres
• Tracing water vapor and ice during dust growth
• Chemistry in Protoplanetary Disks: the gas-phase CO/H2 ratio and the Carbon reservoir
• HD far infrared emission as a measure of protoplanetary disk mass
• Destruction of Refractory Carbon in Protoplanetary Disks
• The First Detection of 13C17O in a Protoplanetary Disk: a Robust Tracer of Disk Gas Mass
• Connecting planet formation and astrochemistry: Refractory carbon depletion leading to super-stellar C/O in giant planetary atmospheres
• Thermal torque effects on the migration of growing low-mass planets
• Debris Disc Constraints on Planetesimal Formation
• The End of Runaway: How Gap Opening Limits the Final Masses of Gas Giants
• Chemistry in a forming protoplanetary disk: main accretion phase
• Physics of Planet Trapping with Applications to HL Tau
• Properties of Density and Velocity Gaps Induced by a Planet in a Protoplanetary Disk

Cited by in corpus (22)

• CO Depletion in Protoplanetary Disks: A Unified Picture Combining Physical Sequestration and Chemical Processing
• The 13O-rich atmosphere of a young accreting super-Jupiter
• Molecules with ALMA at Planet-forming Scales (MAPS). VII. Sub-stellar O/H and C/H and super-stellar C/O in planet feeding gas
• The chemical inventory of the planet-hosting disk PDS 70
• The 12CO/13CO isotopologue ratio of a young, isolated brown dwarf. Possibly distinct formation pathways of super-Jupiters and brown dwarfs
• Observing Carbon & Oxygen Carriers in Protoplanetary Disks at Mid-infrared Wavelengths
• Mapping the Complex Kinematic Substructure in the TW Hya Disk
• The composition of hot Jupiter atmospheres assembled within chemically evolved protoplanetary discs
• Accreting protoplanets: Spectral signatures and magnitude of gas and dust extinction at H alpha
• Moderate-Resolution $K$-Band Spectroscopy of Substellar Companion $\kappa$ Andromedae b
• Chemical Evolution in a Protoplanetary Disk within Planet Carved Gaps and Dust Rings
• The TW Hya Rosetta Stone Project IV: A hydrocarbon rich disk atmosphere
• Inside-Out Planet Formation. VII. Astrochemical Models of Protoplanetary Disks and Implications for Planetary Compositions
• The Molecular Composition of Shadowed Protosolar Disk Midplanes beyond the Water Snowline
• Planet formation in the PDS 70 system: Constraining the atmospheric chemistry of PDS 70b and c
• CO isotopolog line fluxes of viscously evolving disks: cold CO conversion insufficient to explain observed low fluxes
• Iceline Variations Driven by Protoplanetary Disc Gaps
• Gas dynamics around a Jupiter mass planet: II. Chemical evolution of circumplanetary material
• C/O ratios in self-gravitating protoplanetary discs with dust evolution
• Molecules with ALMA at Planet-forming Scales (MAPS) XVII: Determining the 2D Thermal Structure of the HD 163296 Disk
• Interpreting the atmospheric composition of exoplanets: sensitivity to planet formation assumptions
• Linking atmospheric chemistry of the hot Jupiter HD 209458b to its formation location through infrared transmission and emission spectra