Understanding the atmospheric properties and chemical composition of the ultra-hot Jupiter HAT-P-7b II. Mapping the effects of gas kinetics
MetadataShow full item record
Altmetrics Handle Statistics
Altmetrics DOI Statistics
Aims. The atmospheres of ultra-hot Jupiters (UHJs) are commonly considered to be at thermochemical equilibrium. We aim to provide disequilibrium chemistry maps for a global understanding of the chemistry in the atmosphere of HAT-P-7b and assess the importance of disequilibrium chemistry on UHJs. Methods. We applied a hierarchical modeling approach using 97 1D atmospheric profiles from a 3D general circulation model of HAT-P-7b. For each atmospheric 1D profile, we evaluated our kinetic cloud formation model consistently with the local gas-phase composition in chemical equilibrium. This served as input to study the quenching of dominating CHNO-binding molecules. We evaluated quenching results from a zeroth-order approximation in comparison to a kinetic gas-phase approach. Results. We find that the zeroth-order approach of estimating quenching points agrees well with the full gas-kinetic modeling results. However, it underestimates the quenching levels by about one order of magnitude at high temperatures. Chemical disequilibrium has the greatest effect on the nightside and morning abundance of species such as H, H2O, CH4, CO2, HCN, and all CnHm molecules; heavier CnHm molecules are more affected by disequilibrium processes. The CO abundance, however, is affected only marginally. While dayside abundances also notably change, those around the evening terminator of HAT-P-7b are the least affected by disequilibrium processes. The latter finding may partially explain the consistency of observed transmission spectra of UHJs with atmospheres in thermochemical equilibrium. Photochemistry only negligibly affects molecular abundances and quenching levels. Conclusions. In general, the quenching points of the atmosphere of HAT-P-7b are at much lower pressures than in the cooler hot-jupiters. We propose several avenues to determining the effect of disequilibrium processes on UHJs that are in general based on abundance and opacity measurements at different local times. It remains a challenge to completely disentangle this from the chemical effects of clouds and that of a primordial nonsolar abundance.
Molaverdikhani , K , Helling , C , Lew , B W P , MacDonald , R J , Samra , D , Iro , N , Woitke , P & Parmentier , V 2020 , ' Understanding the atmospheric properties and chemical composition of the ultra-hot Jupiter HAT-P-7b II. Mapping the effects of gas kinetics ' , Astronomy & Astrophysics , vol. 635 , A31 . https://doi.org/10.1051/0004-6361/201937044
Astronomy & Astrophysics
Copyright © K. Molaverdikhani et al. 2020. Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
DescriptionFunding: Part of this work was supported by the German Deutsche Forschungsgemeinschaft, DFG project number Ts 17/2–1.
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Showing items related by title, author, creator and subject.
Vanderburg, Andrew; Becker, Juliette C.; Buchhave, Lars A.; Mortier, Annelies; Lopez, Eric; Malavolta, Luca; Haywood, Raphaëlle D.; Latham, David W.; Charbonneau, David; López-Morales, Mercedes; Adams, Fred C.; Bonomo, Aldo Stefano; Bouchy, François; Collier Cameron, Andrew; Cosentino, Rosario; Di Fabrizio, Luca; Dumusque, Xavier; Fiorenzano, Aldo; Harutyunyan, Avet; Johnson, John Asher; Lorenzi, Vania; Lovis, Christophe; Mayor, Michel; Micela, Giusi; Molinari, Emilio; Pedani, Marco; Pepe, Francesco; Piotto, Giampaolo; Phillips, David; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Sozzetti, Alessandro; Udry, Stéphane; Watson, Chris (2017-11-17) - Journal articleWe present precise radial velocity observations of WASP-47, a star known to host a hot Jupiter, a distant Jovian companion, and, uniquely, two additional transiting planets in short-period orbits: a super-Earth in a ≈19 ...
Three newly discovered sub-Jupiter-mass planets : WASP-69b and WASP-84b transit active K dwarfs and WASP-70Ab transits the evolved primary of a G4+K3 binary Anderson, D. R.; Cameron, A. Collier; Delrez, L.; Doyle, A. P.; Faedi, F.; Fumel, A.; Gillon, M.; Chew, Y. Gomez Maqueo; Hellier, C.; Jehin, E.; Lendl, M.; Maxted, P. F. L.; Pepe, F.; Pollacco, D.; Queloz, D.; Segransan, D.; Skillen, I.; Smalley, B.; Smith, A. M. S.; Southworth, J.; Triaud, A. H. M. J.; Turner, O. D.; Udry, S.; West, R. G. (2014-12-01) - Journal articleWe report the discovery of the transiting exoplanets WASP-69b, WASP-70Ab and WASP-84b, each of which orbits a bright star (V ∼ 10). WASP-69b is a bloated Saturn-mass planet (0.26 MJup, 1.06 RJup) in a 3.868-d period around ...
Mayo, Andrew W.; Rajpaul, Vinesh M.; Buchhave, Lars A.; Dressing, Courtney D.; Mortier, Annelies; Zeng, Li; Fortenbach, Charles D.; Aigrain, Suzanne; Bonomo, Aldo S.; Cameron, Andrew Collier; Charbonneau, David; Coffinet, Adrien; Cosentino, Rosario; Damasso, Mario; Dumusque, Xavier; Fiorenzano, A. F. Martinez; Haywood, Raphaëlle D.; Latham, David W.; López-Morales, Mercedes; Malavolta, Luca; Micela, Giusi; Molinari, Emilio; Pearce, Logan; Pepe, Francesco; Phillips, David; Piotto, Giampaolo; Poretti, Ennio; Rice, Ken; Sozzetti, Alessandro; Udry, Stephane (2019-09-27) - Journal articleAlthough several thousands of exoplanets have now been detected and characterized, observational biases have led to a paucity of long-period, low-mass exoplanets with measured masses and a corresponding lag in our understanding ...