Evidence for disequilibrium chemistry from vertical mixing in hot Jupiter atmospheres. A comprehensive survey of transiting close-in gas giant exoplanets with warm-Spitzer/IRAC
arXiv:2103.07185 · doi:10.1051/0004-6361/202039708
Abstract
[Abridged] Aims. We present a large atmospheric study of 49 gas giant exoplanets using infrared transmission photometry with Spitzer/IRAC at 3.6 and 4.5um. Methods. We uniformly analyze 70 photometric light curves of 33 transiting planets using our custom pipeline, which implements pixel level decorrelation. We use this survey to understand how infrared photometry traces changes in atmospheric chemical properties as a function of planetary temperature. We compare our measurements to a grid of 1D radiative-convective equilibrium forward atmospheric models which include disequilibrium chemistry. We explore various strengths of vertical mixing (Kzz = 0 - 10^12 cm2/s) as well as two chemical compositions (1x and 30x solar). Results. We find that, on average, Spitzer probes a difference of 0.5 atmospheric scale heights between 3.6 and 4.5um, which is measured at 7.5sigma level of significance. We find that the coolest planets show a lack of methane compared to expectations, which has also been reported by previous studies of individual objects. We show that the sample of coolest planets rule out 1x solar composition with >3sigma confidence while supporting low vertical mixing (Kzz = 10^8 cm2/s). On the other hand, we find that the hot planets are best explained by models with 1x solar metallicity and high vertical mixing (Kzz = 10^12 cm2/s). We interpret this as the lofting of CH4 to the upper atmospheric layers. Changing the interior temperature changes the expectation for equilibrium chemistry in deep layers, hence the expectation of disequilibrium chemistry higher up. We also find a significant scatter in the transmission signatures of the mid-temperate and ultra-hot planets, likely due to increased atmospheric diversity, without the need to invoke higher metallicities. Additionally, we compare Spitzer transmission with emission for the same planets and find no evidence for correlation.
43 pages, 17 Figures. Accepted on 9 Feb 2021 in Astronomy & Astrophysics
References in corpus (53)
- Detection of Thermal Emission from an Extrasolar Planet
- On the radiative equilibrium of irradiated planetary atmospheres
- Detection of atmospheric haze on an extrasolar planet: The 0.55 - 1.05 micron transmission spectrum of HD189733b with the Hubble Space Telescope
- Accurate, Empirical Radii and Masses of Planets and their Host Stars with Gaia Parallaxes
- Homogeneous studies of transiting extrasolar planets. I. Light curve analyses
- Improving Stellar and Planetary Parameters of Transiting Planet Systems: The Case of TrES-2
- Possible thermochemical disequilibrium in the atmosphere of the exoplanet GJ 436b
- The Broadband Infrared Emission Spectrum of the Exoplanet HD 189733b
- WASP-1b and WASP-2b: Two new transiting exoplanets detected with SuperWASP and SOPHIE
- Spitzer Secondary Eclipses of the Dense, Modestly-irradiated, Giant Exoplanet HAT-P-20b Using Pixel-Level Decorrelation
- An ultrahot gas-giant exoplanet with a stratosphere
- Modeling Kepler transit light curves as false positives: Rejection of blend scenarios for Kepler-9, and validation of Kepler-9d, a super-Earth-size planet in a multiple system
- A Sub-Neptune Exoplanet with a Low-Metallicity Methane-Depleted Atmosphere and Mie-Scattering Clouds
- Mass-Metallicity Trends in Transiting Exoplanets from Atmospheric Abundances of HO, Na, and K
- Methane, Carbon Monoxide, and Ammonia in Brown Dwarfs and Self-Luminous Giant Planets
- VULCAN: an Open-Source, Validated Chemical Kinetics Python Code for Exoplanetary Atmospheres
- HAT-P-26b: A Neptune-Mass Exoplanet with a Well Constrained Heavy Element Abundance
- Changing Phases of Alien Worlds: Probing Atmospheres of Kepler Planets with High-Precision Photometry
- A consistent retrieval analysis of 10 Hot Jupiters observed in transmission
- XO-2b: Transiting Hot Jupiter in a Metal-rich Common Proper Motion Binary
- Empirical, Accurate Masses and Radii of Single Stars with TESS and Gaia
- The Complete transmission spectrum of WASP-39b with a precise water constraint
- The Effects of Consistent Chemical Kinetics Calculations on the Pressure-Temperature Profiles and Emission Spectra of Hot Jupiters
- New Analysis Indicates No Thermal Inversion in the Atmosphere of HD 209458b
- HAT-P-12b: A Low-Density Sub-Saturn Mass Planet Transiting a Metal-Poor K Dwarf
- Forward and Inverse Modeling of the Emission and Transmission Spectrum of GJ 436b: Investigating Metal Enrichment, Tidal Heating, and Clouds
- Spectral Fingerprints of Earth-like Planets Around FGK Stars
- A global analysis of Spitzer and new HARPS data confirms the loneliness and metal-richness of GJ 436 b
- Atmospheric Characterization of the Hot Jupiter Kepler-13Ab
- Beyond Equilibrium Temperature: How the Atmosphere/Interior Connection Affects the Onset of Methane, Ammonia, and Clouds in Warm Transiting Giant Planets
- Deciphering the Atmospheric Composition of WASP-12b: A Comprehensive Analysis of its Dayside Emission
- Thermal Emission of Exoplanet XO-1b
- WASP-80b has a dayside within the T-dwarf range
- The Rotation Period of the Planet-Hosting Star HD 189733
- Spitzer Transits of the Super-Earth GJ1214b and Implications for Its Atmosphere
- Statistical Analysis of Hubble/WFC3 Transit Spectroscopy of Extrasolar Planets
- Observations of Disequilibrium CO Chemistry in the Coldest Brown Dwarfs
- Exoplanet atmospheres with GIANO II. Detection of molecular absorption in the dayside spectrum of HD 102195b
- Analytical Models of Exoplanetary Atmospheres. II. Radiative Transfer via the Two-stream Approximation
- Warm Ice Giant GJ 3470b. II Revised Planetary and Stellar Parameters from Optical to Near-infrared Transit Photometry
- Idealised simulations of the deep atmosphere of hot jupiters: Deep, hot, adiabats as a robust solution to the radius inflation problem
- Sparkling nights and very hot days on WASP-18b: the formation of clouds and the emergence of an ionosphere
- A transition between the hot and the ultra-hot Jupiter atmospheres
- Updated Parameters and a New Transmission Spectrum of HD 97658b
- WASP-94 A and B planets: hot-Jupiter cousins in a twin-star system
- A Hubble PanCET Study of HAT-P-11b: A Cloudy Neptune with a Low Atmospheric Metallicity
- Revisiting Spitzer transit observations with Independent Component Analysis: new results for the GJ436 system
- Characterization of the atmosphere of the hot Jupiter HAT-P-32Ab and the M-dwarf companion HAT-P-32B
- Evidence for disequilibrium chemistry from vertical mixing in hot Jupiter atmospheres. A comprehensive survey of transiting close-in gas giant exoplanets with warm-Spitzer/IRAC
- Colour-magnitude diagrams of transiting Exoplanets - II. A larger sample from photometric distances
- The role of clouds on the depletion of methane and water dominance in the transmission spectra of irradiated exoplanets
- Zodiacal Exoplanets in Time (ZEIT) IX: a flat transmission spectrum and a highly eccentric orbit for the young Neptune K2-25b as revealed by Spitzer
- Colour-colour and colour-magnitude diagrams for Hot Jupiters
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- A Comparative Study of Atmospheric Chemistry with VULCAN
- A warm Neptune's methane reveals core mass and vigorous atmospheric mixing
- Carbon monoxide emission lines reveal an inverted atmosphere in the ultra hot Jupiter WASP-33 b consistent with an eastward hot spot
- JWST transmission spectroscopy of HD 209458b: a super-solar metallicity, a very low C/O, and no evidence of CH4, HCN, or C2H2
- Grid of Pseudo-2D Chemistry Models for Tidally-Locked Exoplanets. I. The Role of Vertical and Horizontal Mixing
- Evidence for disequilibrium chemistry from vertical mixing in hot Jupiter atmospheres. A comprehensive survey of transiting close-in gas giant exoplanets with warm-Spitzer/IRAC
- 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
- Grid of pseudo-2D chemistry models for tidally locked exoplanets -- II. The role of photochemistry
- TESS Giants Transiting Giants II: The hottest Jupiters orbiting evolved stars
- A New Analysis of 8 Spitzer Phase Curves and Hot Jupiter Population Trends: Qatar-1b, Qatar-2b, WASP-52b, WASP-34b, and WASP-140b
- Strong HO and CO emission features in the spectrum of KELT-20b driven by stellar UV irradiation
- Two long-period transiting exoplanets on eccentric orbits: NGTS-20 b (TOI-5152 b) and TOI-5153 b
- A Mini-Chemical Scheme with Net Reactions for 3D GCMs I.: Thermochemical Kinetics
- The metal-poor atmosphere of a Neptune/Sub-Neptune planet progenitor
- Featureless transmission spectra of 12 giant exoplanets observed by GTC/OSIRIS
- First Comparative Exoplanetology Within a Transiting Multi-planet System: Comparing the atmospheres of V1298 Tau b and c
- Photodissociation and induced chemical asymmetries on ultra-hot gas giants. A case study of HCN on WASP-76 b
- The COBREX archival survey: improved constraints on the occurrence rate of wide-orbit substellar companions. I. A uniform re-analysis of 400 stars from the GPIES survey
- The infrared colors of 51 Eridani b: micrometereoid dust or chemical disequilibrium?
- The Hubble PanCET program: Transit and Eclipse Spectroscopy of the Hot Jupiter WASP-74b
- Probing reflection from aerosols with the near-infrared dayside spectrum of WASP-80b
- GEMS JWST: Transmission spectroscopy of TOI-5205b reveals significant stellar contamination and a metal-poor atmosphere
- Using a neural network approach to accelerate disequilibrium chemistry calculations in exoplanet atmospheres
- The Hubble PanCET program: Emission spectrum of hot Jupiter HAT-P-41b
- Kinetic and photochemical disequilibrium in the potentially carbon-rich atmosphere of the warm-Jupiter WASP-69b
- The Hubble PanCET Program: A Featureless Transmission Spectrum for WASP-29b and Evidence of Enhanced Atmospheric Metallicity on WASP-80b
- A Cloudy Fit to the Atmosphere of WASP-107 b
- The HUSTLE Program: The UV to Near-IR Transmission Spectrum of the Hot Jupiter KELT-7b