The composition of hot Jupiter atmospheres assembled within chemically evolved protoplanetary discs

Abstract

The radial-dependent positions of snowlines of abundant oxygen- and carbon-bearing molecules in protoplanetary discs will result in systematic radial variations in the C/O ratios in the gas and ice. This variation is proposed as a tracer of the formation location of gas-giant planets. However, disc chemistry can affect the C/O ratios in the gas and ice, thus potentially erasing the chemical fingerprint of snowlines in gas-giant atmospheres. We calculate the molecular composition of hot Jupiter atmospheres using elemental abundances extracted from a chemical kinetics model of a disc midplane where we have varied the initial abundances and ionization rates. The models predict a wider diversity of possible atmospheres than those predicted using elemental ratios from snowlines only. As found in previous work, as the C/O ratio exceeds the solar value, the mixing ratio of CH${}_4$ increases in the lower atmosphere, and those of C${}_2$H${}_2$ and HCN increase mainly in the upper atmosphere. The mixing ratio of H${}_2$O correspondingly decreases. We find that hot Jupiters with C/O$>1$ can only form between the CO${}_2$ and CH${}_4$ snowlines. Moreover, they can only form in a disc which has fully inherited interstellar abundances, and where negligible chemistry has occurred. Hence, carbon-rich planets are likely rare, unless efficient transport of hydrocarbon-rich ices via pebble drift to within the CH${}_4$ snowline is a common phenomenon. We predict combinations of C/O ratios and elemental abundances that can constrain gas-giant planet formation locations relative to snowline positions, and that can provide insight into the disc chemical history.

arXiv comment18 pages, 7 figures, and 2 tables are contained in this paper. It was accepted for publication in MNRAS on September 18th, 2020

References in corpus (97)

• The chemical composition of the Sun
• First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region
• The Disk Substructures at High Angular Resolution Project (DSHARP): I. Motivation, Sample, Calibration, and Overview
• The effects of snowlines on C/O in planetary atmospheres
• Towards a Deterministic Model of Planetary Formation I: a Desert in the Mass and Semi Major Axis Distributions of Extra Solar Planets
• The Occurrence and Architecture of Exoplanetary Systems
• The orbital motion, absolute mass, and high-altitude winds of exoplanet HD209458b
• A Unified Theory for the Atmospheres of the Hot and Very Hot Jupiters: Two Classes of Irradiated Atmospheres
• Ringed Substructure and a Gap at 1 AU in the Nearest Protoplanetary Disk
• On the radiative equilibrium of irradiated planetary atmospheres
• Disequilibrium Carbon, Oxygen, and Nitrogen Chemistry in the Atmospheres of HD 189733b and HD 209458b
• The Disk Substructures at High Angular Resolution Project (DSHARP): II. Characteristics of Annular Substructures
• C/O ratio as a Dimension for Characterizing Exoplanetary Atmospheres
• Dust and Gas in the disc of HL Tauri: Surface density, dust settling, and dust-to-gas ratio
• A Precise Water Abundance Measurement for the Hot Jupiter WASP-43b
• The Exoplanet Orbit Database
• Detection of Carbon Monoxide and Water Absorption Lines in an Exoplanet Atmosphere
• The imprint of exoplanet formation history on observable present-day spectra of hot Jupiters
• Characterizing transiting exoplanet atmospheres with JWST
• Exoplanetary Atmospheres: Key Insights, Challenges and Prospects
• High C/O Ratio and Weak Thermal Inversion in the Very Hot Atmosphere of Exoplanet WASP-12b
• Characterization of exoplanets from their formation I: Models of combined planet formation and evolution
• Possible thermochemical disequilibrium in the atmosphere of the exoplanet GJ 436b
• Chemical consequences of the C/O ratio on hot Jupiters: Examples from WASP-12b,CoRoT-2b, XO-1b, and HD 189733b
• Retrieving Temperatures and Abundances of Exoplanet Atmospheres with High-Resolution Cross-Correlation Spectroscopy
• A chemical model for the atmosphere of hot Jupiters
• Rotation and winds of exoplanet HD 189733 b measured with high-dispersion transmission spectroscopy
• Chemical enrichment of giant planets and discs due to pebble drift
• Radial migration of gap-opening planets in protoplanetary disks. I. The case of a single planet
• Model atmospheres of irradiated exoplanets: The influence of stellar parameters, metallicity, and the C/O ratio
• Distribution of Accreting Gas and Angular Momentum onto Circumplanetary Disks
• Retrieving scattering clouds and disequilibrium chemistry in the atmosphere of HR 8799e
• A Systematic Retrieval Analysis of Secondary Eclipse Spectra II: A Uniform Analysis of Eight Planets and Their C to O Ratios
• VULCAN: an Open-Source, Validated Chemical Kinetics Python Code for Exoplanetary Atmospheres
• Exclusion of Cosmic Rays in Protoplanetary Disks: Stellar and Magnetic Effects
• Exoplanetary Atmospheres - Chemistry, Formation Conditions, and Habitability
• Meridional flows in the disk around a young star
• The molecular composition of the planet-forming regions of protoplanetary disks across the luminosity regime
• Quenching of Carbon Monoxide and Methane in the Atmospheres of Cool Brown Dwarfs and Hot Jupiters
• The Disk Substructures at High Angular Resolution Project (DSHARP) - IX. A high definition study of the HD 163296 planet forming disk
• Atmospheric Signatures of Giant Exoplanet Formation by Pebble Accretion
• Setting the volatile composition of (exo)planet-building material. Does chemical evolution in disk midplanes matter?
• Atom addition reactions in interstellar ice analogues
• ALMA continuum observations of the protoplanetary disk AS 209. Evidence of multiple gaps opened by a single planet
• Molecular abundances and C/O ratios in chemically evolving planet-forming disk midplanes
• Spectral and atmospheric characterization of 51 Eridani b using VLT/SPHERE
• First direct detection of an exoplanet by optical interferometry; Astrometry and K-band spectroscopy of HR8799 e
• Formation of a disc gap induced by a planet: Effect of the deviation from Keplerian disc rotation
• Meridional circulation of gas into gaps opened by giant planets in three-dimensional low-viscosity disks
• The water abundance in Jupiter's equatorial zone
• Discovery of water at high spectral resolution in the atmosphere of 51 Peg b
• Planet-forming material in a protoplanetary disc: the interplay between chemical evolution and pebble drift
• CO destruction in protoplanetary disk midplanes: inside versus outside the CO snow surface
• Jupiter's composition suggests its core assembled exterior to the N2 snowline
• Uniform Atmospheric Retrieval Analysis of Ultracool Dwarfs II: Properties of 11 T-dwarfs
• Giant Planet Formation, Evolution, and Internal Structure
• Evolution of Molecular Abundance in Protoplanetary Disks
• Excess C/O and C/H in outer protoplanetary disk gas
• Disk evolution, element abundances and cloud properties of young gas giant planets
• On the robustness of analysis techniques for molecular detections using high resolution exoplanet spectroscopy
• A Gap with a Deficit of Large Grains in the protoplanetary disk around TW Hya
• Ground-based NIR emission spectroscopy of HD189733b
• Exoplanet atmospheres with GIANO II. Detection of molecular absorption in the dayside spectrum of HD 102195b
• Connecting planet formation and astrochemistry: A main sequence for C/O in hot-exoplanetary atmospheres
• TEA: A Code for Calculating Thermochemical Equilibrium Abundances
• Evidence for multiple molecular species in the hot Jupiter HD 209458b
• Evolutionary Tracks of Trapped, Accreting Protoplanets: the Origin of the Observed Mass-Period Relation
• Slowing Down Type II Migration of Gas Giants to Match Observational Data
• C/O and O/H Ratios Suggest Some Hot Jupiters Originate Beyond the Snow Line
• Disk Substructures at High Angular Resolution Program (DSHARP): VIII. The Rich Ringed Substructures in the AS 209 Disk
• The Role of Ice Compositions for Snowlines and the C/N/O Ratios in Active Disks
• Towards Consistent Modeling of Atmospheric Chemistry and Dynamics in Exoplanets: Validation and Generalization of Chemical Relaxation Method
• A Systematic Retrieval Analysis of Secondary Eclipse Spectra III: Diagnosing Chemical Disequilibrium in Planetary Atmospheres
• Connecting planet formation and astrochemistry: Refractory carbon depletion leading to super-stellar C/O in giant planetary atmospheres
• Measuring Jupiter's water abundance by Juno: the link between interior and formation models
• Jupiter formed as a pebble pile around the N${}_2$ ice line
• Composition of Early Planetary Atmospheres II: Coupled Dust and Chemical Evolution in Protoplanetary Disks
• Analytical Models of Exoplanetary Atmospheres. III. Gaseous C-H-O-N Chemistry with 9 Molecules
• The chemistry of protoplanetary fragments formed via gravitational instabilities
• Signatures of Nitrogen Chemistry in Hot Jupiter Atmospheres
• From cold to hot irradiated gaseous exoplanets: Fingerprints of chemical disequilibrium in atmospheric spectra
• Disk masses around solar-mass stars are underestimated by CO observations
• On the Formation and Chemical Composition of Super Earths
• Candidate Water Vapor Lines to Locate the H${}_2$O Snowline through High-Dispersion Spectroscopic Observations II. The Case of a Herbig Ae Star
• Candidate Water Vapor Lines to Locate the H${}_2$O Snowline through High-Dispersion Spectroscopic Observations I. The Case of a T Tauri Star
• Alfnoor: A Retrieval Simulation of the Ariel Target List
• A chemical kinetics code for modelling exoplanetary atmospheres
• The carbon-to-oxygen ratio: implications for the spectra of hydrogen-dominated exoplanet atmospheres
• Exoplanetary Atmospheres
• Clear and Cloudy Exoplanet Forecasts for JWST: Maps, Retrieved Composition and Constraints on Formation with MIRI and NIRCam
• Dust continuum emission and the upper limit fluxes of sub-millimeter water lines of the protoplanetary disk around HD 163296 observed by ALMA
• Inferring (Sub)millimeter Dust Opacities and Temperature Structure in Edge-on Protostellar Disks From Resolved Multi-Wavelength Continuum Observations: The Case of the HH 212 Disk
• Vertical gas accretion impacts the carbon-to-oxygen ratio of gas giant atmospheres
• A better characterization of the chemical composition of exoplanets atmospheres with ARIEL
• The role of OH in the chemical evolution of protoplanetary disks. I. The comet-forming region
• Spectroscopic Coronagraphy for Planetary Radial Velocimetry of Exoplanets
• Pebble accretion in class 0/I YSOs as a possible pathway for early planet formation

Cited by in corpus (26)

• How drifting and evaporating pebbles shape giant planets I: Heavy element content and atmospheric C/O
• A New Window into Planet Formation and Migration: Refractory-to-Volatile Elemental Ratios in Ultra-hot Jupiters
• How drifting and evaporating pebbles shape giant planets II: Volatiles and refractories in atmospheres
• Grid of Pseudo-2D Chemistry Models for Tidally-Locked Exoplanets. I. The Role of Vertical and Horizontal Mixing
• Implementation of disequilibrium chemistry to spectral retrieval code ARCiS and application to sixteen exoplanet transmission spectra: Indication of disequilibrium chemistry for HD 209458b and WASP-39b
• Evidence that the Hot Jupiter WASP-77 A b Formed Beyond Its Parent Protoplanetary Disk's H2O Ice Line
• Nitrogen as a Tracer of Giant Planet Formation. I.: A Universal Deep Adiabatic Profile and Semi-analytical Predictions of Disequilibrium Ammonia Abundances in Warm Exoplanetary Atmospheres
• X-ray induced chemistry of water and related molecules in low-mass protostellar envelopes
• Jupiter's "Cold" Formation in the Protosolar Disk Shadow: An Explanation for the Planet's Uniformly Enriched Atmosphere
• BOWIE-ALIGN: How formation and migration histories of giant planets impact atmospheric compositions
• SimAb: A simple, fast and flexible model to assess the effects of planet formation on the atmospheric composition of gas giants
• System-level fractionation of carbon from disk and planetesimal processing
• Chemical evolution in ices on drifting, planet-forming pebbles
• High Spatial Resolution Observations of Molecular Lines towards the Protoplanetary Disk around TW Hya with ALMA
• Formation of dust clumps with sub-Jupiter mass and cold shadowed region in gravitationally unstable disk around Class 0/I protostar in L1527 IRS
• The origin of the high metallicity of close-in giant exoplanets II The nature of the sweet spot for accretion
• The Molecular Composition of Shadowed Protosolar Disk Midplanes beyond the Water Snowline
• Tracing the formation and migration history: molecular signatures in the atmosphere of misaligned hot Jupiter WASP-94Ab using JWST NIRSpec/G395H
• Ariel stellar characterisation II. Chemical abundances of carbon, nitrogen, and oxygen for 181 planet-host FGK dwarf stars
• Constraining the formation of WASP-39b using JWST transit spectroscopy
• Chemical evolution in planet-forming regions with growing grains
• Zodiacal Exoplanets in Time (ZEIT) XII: A Directly-Imaged Planetary-Mass Companion to a Young Taurus M Dwarf Star
• Retrieving planet formation parameters of WASP-77Ab using SimAb
• Icy Volatile Enhancements in Evolving Protoplanetary Disks
• The formation of planetary systems with SPICA
• Linking atmospheric chemistry of the hot Jupiter HD 209458b to its formation location through infrared transmission and emission spectra