Interior-atmosphere modelling to assess the observability of rocky planets with JWST

Abstract

There is a degeneracy in the interior structure between a planet that has no atmosphere and a small Fe content, and a planet that has a thin atmosphere and a higher core mass fraction. We present a self-consistent interior-atmosphere model to constrain the volatile mass fraction, surface pressure, and temperature of rocky planets with water and CO${}_2$ atmospheres. The parameters obtained in our analysis can be used to predict observations in emission spectroscopy and photometry with JWST, which can determine the presence of an atmosphere and, if present, its composition. We coupled a 1D interior model with a supercritical water layer to an atmospheric model. In order to obtain the bolometric emission and Bond albedo for an atmosphere in radiative-convective equilibrium, we used a low-resolution k-correlated model within our retrieval of planetary mass, radius, and host stellar abundances. We generated emission spectra with the same model at a higher resolution (R = 200-300). An adaptive Markov chain Monte Carlo was employed for an efficient sampling of the parameter space at low volatile mass fractions. From our interior structure retrieval, TRAPPIST-1 c is most likely to present a bare surface, although the presence of an atmosphere cannot be ruled out. We estimate a 1$\sigma$ confidence interval of the surface pressure for a water-dominated atmosphere of $P_{surf}=40\pm 40$ bar. We generated spectra for these two scenarios to compare with the emission flux of TRAPPIST-1 c recently observed in the MIRI F1500W filter. This is compatible with bare rock surfaces or a thin atmosphere with little or no CO${}_2$. In the case of 55 Cancri e, a combined spectrum with NIRCam and MIRI LRS may present high uncertainties at wavelengths between 3 and 3.7 $\mu$m. However, this does not affect the identification of H${}_2$O because it does not present spectral features in this wavelength range.

arXiv comment14 pages, 6 figures. Accepted for publication in A&A

References in corpus (61)

• emcee: The MCMC Hammer
• The James Webb Space Telescope
• Habitable Zones Around Main-Sequence Stars: New Estimates
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• Understanding the Mass-Radius Relation for Sub-Neptunes: Radius as a Proxy for Composition
• Temperate Earth-sized planets transiting a nearby ultracool dwarf star
• ExoMol molecular line lists XXX: a complete high-accuracy line list for water
• The California Kepler Survey VII. Precise Planet Radii Leveraging Gaia DR2 Reveal the Stellar Mass Dependence of the Planet Radius Gap
• C/O ratio as a Dimension for Characterizing Exoplanetary Atmospheres
• Can we constrain interior structure of rocky exoplanets from mass and radius measurements?
• The nature of the TRAPPIST-1 exoplanets
• Increased insolation threshold for runaway greenhouse processes on Earth like planets
• Atmospheric Sulfur Photochemistry on Hot Jupiters
• Absence of a thick atmosphere on the terrestrial exoplanet LHS 3844b
• Thermal emission from the Earth-sized exoplanet TRAPPIST-1 b using JWST
• The Detectability and Characterization of the TRAPPIST-1 Exoplanet Atmospheres with JWST
• Detection of an atmosphere around the super-Earth 55 Cancri e
• A generalized bayesian inference method for constraining the interiors of super Earths and sub-Neptunes
• No thick carbon dioxide atmosphere on the rocky exoplanet TRAPPIST-1 c
• Detection of a transit of the super-Earth 55 Cnc e with Warm Spitzer
• HELIOS-K: An Ultrafast, Open-source Opacity Calculator for Radiative Transfer
• HELIOS: An Open-source, GPU-accelerated Radiative Transfer Code For Self-consistent Exoplanetary Atmospheres
• A reflective, metal-rich atmosphere for GJ 1214b from its JWST phase curve
• Hint of a transiting extended atmosphere on 55 Cancri b
• AQUA: A Collection of H${}_2$O Equations of State for Planetary Models
• Abundances in the Local Region II: F, G and K Dwarfs and Subgiants
• Self-luminous and irradiated exoplanetary atmospheres explored with HELIOS
• The Atmospheres of Earth-like Planets after Giant Impact Events
• MIRACLES: atmospheric characterization of directly imaged planets and substellar companions at 4-5 $\mu$m. I. Photometric analysis of $\beta$ Pic b, HIP 65426 b, PZ Tel B and HD 206893 B
• Theoretical Spectra of Terrestrial Exoplanet Surfaces
• The interior and atmosphere of the habitable-zone exoplanet K2-18b
• The 55 Cnc system reassessed
• Irradiated ocean planets bridge super-Earth and sub-Neptune populations
• Mass-radius relationships for irradiated ocean planets
• The Mid-Infrared Instrument for the James Webb Space Telescope, IX: Predicted Sensitivity
• Linking the Climate and Thermal Phase Curve of 55 Cancri e
• Constraints on Super-Earths Interiors from Stellar Abundances
• Search for water in a super-Earth atmosphere: High-resolution optical spectroscopy of 55 Cancri e
• Ab initio based equation of state of dense water for planetary and exoplanetary modeling
• A Case for an Atmosphere on Super-Earth 55 Cancri e
• A new perspective on interiors of ice-rich planets: Ice-rock mixture instead of ice on top of rock
• K2 and Spitzer phase curves of the rocky ultra-short-period planet K2-141 b hint at a tenuous rock vapor atmosphere
• Characterisation of the hydrospheres of TRAPPIST-1 planets
• Constraining the Thickness of the Atmosphere of TRAPPIST-1 b from its JWST Secondary Eclipse Observation
• Predicted diversity in water content of terrestrial exoplanets orbiting M dwarfs
• No escaping helium from 55 Cnc e
• A Heavy Molecular Weight Atmosphere for the Super-Earth π Men c
• Jupiter's formation in the vicinity of the amorphous ice snowline
• Modeling the albedo of Earth-like magma ocean planets with H2O-CO2 atmospheres
• The importance of silicate vapor in determining the structure, radii, and envelope mass fractions of sub-Neptunes
• Spectral binning of precomputed correlated-k coefficients
• Possible Internal Structures and Compositions of Proxima Centauri b
• Methane as a dominant absorber in the habitable-zone sub-Neptune K2-18 b
• Optical Transmission Spectroscopy of the Terrestrial Exoplanet LHS 3844b from 13 Ground-Based Transit Observations
• The PEPSI Exoplanet Transit Survey (PETS) I: Investigating the presence of a silicate atmosphere on the super-Earth 55 Cnc e
• Waterworlds Probably Do Not Experience Magmatic Outgassing
• The Effect of Clouds as an Additional Opacity Source on the Inferred Metallicity of Giant Exoplanets
• Measurements and modeling of absorption by CO2+H2O mixtures in the spectral region beyond the CO2 nu3-band head
• Water content trends in K2-138 and other low-mass multiplanetary systems
• TOI-220 $b$: a warm sub-Neptune discovered by TESS
• An Equation of State of CO for use in Planetary Modeling

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• No thick carbon dioxide atmosphere on the rocky exoplanet TRAPPIST-1 c
• An unusually low-density super-Earth transiting the bright early-type M-dwarf GJ 1018 (TOI-244)
• Escaping Helium and a Highly Muted Spectrum Suggest a Metal-Enriched Atmosphere on Sub-Neptune GJ3090b from JWST Transit Spectroscopy
• GASTLI: An open-source coupled interior-atmosphere model to unveil gas giant composition
• Redox evolution of the crystallizing terrestrial magma ocean and its influence on atmosphere outgassing
• Volatile atmospheres of lava worlds
• TOI-4438 b: a transiting mini-Neptune amenable to atmospheric characterization
• From CO${}_2$- to H${}_2$O-dominated atmospheres and back -- How mixed outgassing changes the volatile distribution in magma oceans around M dwarf stars