The Hazy and Metal-Rich Atmosphere of GJ 1214 b Constrained by Near and Mid-Infrared Transmission Spectroscopy

Abstract

The near-infrared transmission spectrum of the warm sub-Neptune exoplanet GJ 1214 b has been observed to be flat and featureless, implying a high metallicity atmosphere with abundant aerosols. Recent JWST MIRI LRS observations of a phase curve of GJ 1214 b showed that its transmission spectrum is flat out into the mid-infrared. In this paper, we use the combined near- and mid-infrared transmission spectrum of GJ 1214 b to constrain its atmospheric composition and aerosol properties. We generate a grid of photochemical haze models using an aerosol microphysics code for a number of background atmospheres spanning metallicities from 100 to 1000 $\times$ solar, as well as a steam atmosphere scenario. The flatness of the combined data set largely rules out atmospheric metallicities $\le$300 $\times$ solar due to their large corresponding molecular feature amplitudes, preferring values $\ge$1000 $\times$ solar and column haze production rates $\ge$10${}^{-10}$ g cm${}^{-2}$ s${}^{-1}$. The steam atmosphere scenario with similarly high haze production rates also exhibit sufficiently small molecular features to be consistent with the transmission spectrum. These compositions imply that atmospheric mean molecular weights $\ge$15 g mol${}^{-1}$ are needed to fit the data. Our results suggest that haze production is highly efficient on GJ 1214 b and could involve non-hydrocarbon, non-nitrogen haze precursors. Further characterization of GJ 1214 b's atmosphere would likely require multiple transits and eclipses using JWST across the near and mid-infrared, potentially complemented by groundbased high resolution transmission spectroscopy.

arXiv comment21 pages, 10 figures, 4 tables. Accepted for publication by ApJ

References in corpus (93)

• The chemical composition of the Sun
• Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b
• Precipitating Condensation Clouds in Substellar Atmospheres
• A super-Earth transiting a nearby low-mass star
• Understanding the Mass-Radius Relation for Sub-Neptunes: Radius as a Proxy for Composition
• ExoMol molecular line lists XXX: a complete high-accuracy line list for water
• An asteroseismic view of the radius valley: stripped cores, not born rocky
• ExoMol line lists IV: The rotation-vibration spectrum of methane up to 1500 K
• Transmission Spectra as Diagnostics of Extrasolar Giant Planet Atmospheres
• A ground-based transmission spectrum of the super-Earth exoplanet GJ1214b
• 3D mixing in hot Jupiter atmospheres. I. application to the day/night cold trap in HD 209458b
• Gaseous Mean Opacities for Giant Planet and Ultracool Dwarf Atmospheres over a Range of Metallicities and Temperatures
• A variationally computed line list for hot NH3
• The Flat Transmission Spectrum of the Super-Earth GJ1214b from Wide Field Camera 3 on the Hubble Space Telescope
• PandExo: A Community Tool for Transiting Exoplanet Science with JWST & HST
• A Framework for Characterizing the Atmospheres of Low-Mass Low-Density Transiting Planets
• Density, not radius, separates rocky and water-rich small planets orbiting M dwarf stars
• Compositional diversity in the atmospheres of hot Neptunes, with application to GJ 436b
• Comparative Planetary Atmospheres: Models of TrES-1 and HD209458b
• Photochemically-produced SO${}_2$ in the atmosphere of WASP-39b
• Thermal Emission and Albedo Spectra of Super Earths with Flat Transmission Spectra
• Three Possible Origins for the Gas Layer on GJ 1214b
• Improved HCN/HNC linelist, model atmospheres and synthetic spectra for WZ Cas
• Transmission spectral properties of clouds for hot Jupiter exoplanets
• Quantitatively Assessing the Role of Clouds in the Transmission Spectrum of GJ 1214b
• Bulk Composition of GJ 1214b and other sub-Neptune exoplanets
• The Optical and Near-Infrared Transmission Spectrum of the Super-Earth GJ1214b: Further Evidence for a Metal-Rich Atmosphere
• Thermal evolution and structure models of the transiting super-Earth GJ 1214b
• Early Release Science of the exoplanet WASP-39b with JWST NIRCam
• Identification of carbon dioxide in an exoplanet atmosphere
• Observational evidence for a metal rich atmosphere on the super-Earth GJ1214b
• The Atmospheric Chemistry of GJ 1214b: Photochemistry and Clouds
• Photochemistry in Terrestrial Exoplanet Atmospheres III: Photochemistry and Thermochemistry in Thick Atmospheres on Super Earths and Mini Neptunes
• ACCESS I: An Optical Transmission Spectrum of GJ 1214b Reveals a Heterogeneous Stellar Photosphere
• FastChem: A computer program for efficient complex chemical equilibrium calculations in the neutral/ionized gas phase with applications to stellar and planetary atmospheres
• A reflective, metal-rich atmosphere for GJ 1214b from its JWST phase curve
• On the Indirect Detection of Sodium in the Atmosphere of the Planetary Companion to HD 209458
• Exoplanet albedo spectra and colors as a function of planet phase, separation, and metallicity
• Partition functions and equilibrium constants for diatomic molecules and atoms of astrophysical interest
• The Nature of the Atmosphere of the Transiting Super-Earth GJ 1214b
• Quantifying and Predicting the Presence of Clouds in Exoplanet Atmospheres
• New H2 collision-induced absorption and NH3 opacity and the spectra of the coolest brown dwarfs
• GENESIS: New Self-Consistent Models of Exoplanetary Spectra
• PICASO 3.0: A One-Dimensional Climate Model for Giant Planets and Brown Dwarfs
• Haze Production in the Atmospheres of super-Earths and mini-Neptunes: Insights from the Lab
• The Mid-Infrared Instrument for the James Webb Space Telescope: IV. The Low Resolution Spectrometer
• 3D modeling of GJ1214b's atmosphere: formation of inhomogeneous high clouds and observational implications
• 3D modeling of GJ1214b's atmosphere: vertical mixing driven by an anti-Hadley circulation
• Aerosols in Exoplanet Atmospheres
• Theoretical transmission spectra of exoplanet atmospheres with hydrocarbon haze: Effect of creation, growth, and settling of haze particles. I. Model description and first results
• Vibrational transition moments of CH${}_4$ from first principles
• FastChem 2: An improved computer program to determine the gas-phase chemical equilibrium composition for arbitrary element distributions
• High Resolution, Differential, Near-infrared Transmission Spectroscopy of GJ 1214b
• Conclusive evidence for a population of water-worlds around M-dwarfs remains elusive
• Sedimentation Efficiency of Condensation Clouds in Substellar Atmospheres
• Spitzer Transits of the Super-Earth GJ1214b and Implications for Its Atmosphere
• Effects of Bulk Composition on The Atmospheric Dynamics on Close-in Exoplanets
• Microphysics of KCl and ZnS Clouds on GJ 1214b
• Optical to near-infrared transit observations of super-Earth GJ1214b: water-world or mini-Neptune?
• Deflating Super-Puffs: Impact of Photochemical Hazes on the Observed Mass-Radius Relationship of Low Mass Planets
• The atmospheric circulation of the super Earth GJ 1214b: Dependence on composition and metallicity
• Analysis of a JWST NIRSpec Lab Time Series: Characterizing Systematics, Recovering Exoplanet Transit Spectroscopy, and Constraining a Noise Floor
• TRIDENT: A Rapid 3D Radiative Transfer Model for Exoplanet Transmission Spectra
• 3D simulations of photochemical hazes in the atmosphere of hot Jupiter HD 189733b
• EXOPLINES: Molecular Absorption Cross-Section Database for Brown Dwarf and Giant Exoplanet Atmospheres
• The effect of metallicity on the atmospheres of exoplanets with fully coupled 3D hydrodynamics, equilibrium chemistry, and radiative transfer
• Aggregate Hazes in Exoplanet Atmospheres
• A More Precise Mass for GJ 1214 b and the Frequency of Multi-Planet Systems Around Mid-M Dwarfs
• Sulfur-driven Haze Formation in Warm CO2-rich Exoplanet Atmospheres
• How Deep Is the Ocean? Exploring the phase structure of water-rich sub-Neptunes
• Microphysical Modeling of Mineral Clouds in GJ1214 b and GJ436 b: Predicting Upper Limits on the Cloud-Top Height
• Non-detection of Helium in the Upper Atmospheres of Three Sub-Neptune Exoplanets
• The spectrum of N${}_2$ from 4,500 to 15,700 cm${}^{-1}$ revisited with PGOPHER
• Photochemical hazes in sub-Neptunian atmospheres with focus on GJ 1214 b
• IRSF SIRIUS JHKs Simultaneous Transit Photometry of GJ1214b
• Detectable molecular features above hydrocarbon haze via transmission spectroscopy with JWST: Case studies of GJ 1214b-, GJ 436b-, HD 97658b-, and Kepler-51b-like planets
• Seeing above the Clouds with High Resolution Spectroscopy
• A tentative detection of He I in the atmosphere of GJ 1214b
• On the Temperature Profiles and Emission Spectra of Mini-Neptune Atmospheres
• Clouds of Fluffy Aggregates: How They Form in Exoplanetary Atmospheres and Influence Transmission Spectra
• Haze Evolution in Temperate Exoplanet Atmospheres Through Surface Energy Measurements
• A planetary system with two transiting mini-Neptunes near the radius valley transition around the bright M dwarf TOI-776
• Prospects for Characterizing the Haziest Sub-Neptune Exoplanets with High Resolution Spectroscopy
• A Search for Methane in the Atmosphere of GJ 1214b via GTC Narrow-Band Transmission Spectrophotometry
• A New Sedimentation Model for Greater Cloud Diversity in Giant Exoplanets and Brown Dwarfs
• Narrow-K-Band Observations of the GJ 1214 System
• Optical Observations of the Transiting Exoplanet GJ 1214b
• Assessing Spectra and Thermal Inversions due to TiO in Hot Jupiter Atmospheres
• The Impact of Phase Equilibrium Cloud Models on GCM Simulations of GJ~1214b
• JWST NIRCam Defocused Imaging: Photometric Stability Performance and How it Can Sense Mirror Tilts
• Photochemical hazes can trace the C/O ratio in exoplanet atmospheres
• The hot Neptune WASP-166 b with ESPRESSO III: A blue-shifted tentative water signal constrains the presence of clouds
• Precise mass determination for the keystone sub-Neptune planet transiting the mid-type M dwarf G 9-40

Cited by in corpus (28)

• Clouds and Clarity: Revisiting Atmospheric Feature Trends in Neptune-size Exoplanets
• Escaping Helium and a Highly Muted Spectrum Suggest a Metal-Enriched Atmosphere on Sub-Neptune GJ3090b from JWST Transit Spectroscopy
• Multiple Clues for Dayside Aerosols and Temperature Gradients in WASP-69 b from a Panchromatic JWST Emission Spectrum
• Role of magma oceans in controlling carbon and oxygen of sub-Neptune atmospheres
• The metal-poor atmosphere of a Neptune/Sub-Neptune planet progenitor
• Dynamics and Clouds in Planetary Atmospheres from Telescopic Observations
• Magma ocean interactions can explain JWST observations of the sub-Neptune TOI-270 d
• Clouds and Hazes in GJ 1214b's Metal-Rich Atmosphere
• Constraining exoplanet interiors using observations of their atmospheres
• Three-dimensional dynamical evolution of cloud particle microphysics in sub-stellar atmospheres I. Description and exploring Y-dwarf atmospheric variability
• An extensively validated C/H/O/N chemical network for hot exoplanet disequilibrium chemistry
• Looking For Timing Variations in the Transits of 16 Exoplanets
• Diversity in the haziness and chemistry of temperate sub-Neptunes
• Cloudy mornings and clear evenings on a gas giant exoplanet
• Probing reflection from aerosols with the near-infrared dayside spectrum of WASP-80b
• Carbon-rich Sub-Neptune Interiors Are Compatible with JWST Observations
• Not All Sub-Neptune Exoplanets Have Magma Oceans
• Light Scattering Measurements of KCl Particles as an Exoplanet Cloud Analog
• Tidally Heated Sub-Neptunes, Refined Planetary Compositions, and Confirmation of a Third Planet in the TOI-1266 System
• Investigating aerosols as a way to reconcile K2-18 b JWST MIRI and NIRISS/NIRSpec observations
• Reflected-light Phase Curves with PICASO: A Kepler-7b Case Study
• The Effects of Cuboid Particle Scattering on Reflected Light Phase Curves: Insights from Laboratory Data and Theory
• A Pair of Dynamically Interacting Sub-Neptunes Around TOI-6054
• Hot Rocks Survey V: Secondary Eclipse Photometry of GJ 3473 b with JWST/MIRI
• Characterizing the bolometric-photoevaporative transition in young sub-Neptunes with radiation-hydrodynamic simulations
• Impact of Clouds on the Atmosphere-Mantle Interface of Sub-Neptunes
• Chemistry, Climate, and Transmission Spectra of TRAPPIST-1 e Explored with a Multimodel Sparse Sampled Ensemble
• Influence of CO versus CH${}_4$ on organic haze formation in atmospheres of diverse terrestrial exoplanets