dc.contributor.author Welbanks, L dc.contributor.author Madhusudhan, N dc.date.accessioned 2022-07-05T20:00:14Z dc.date.available 2022-07-05T20:00:14Z dc.date.issued 2022 dc.date.submitted 2021-12-16 dc.identifier.citation The Astrophysical Journal, volume 933, issue 1, article-number 79 dc.identifier.issn 0004-637X dc.identifier.other apjac6df1 dc.identifier.other ac6df1 dc.identifier.other aas36653 dc.identifier.uri https://www.repository.cam.ac.uk/handle/1810/338821 dc.description.abstract The complexity of atmospheric retrieval models is largely data-driven and one-dimensional models have generally been considered adequate with current data quality. However, recent studies have suggested that using 1D models in retrievals can result in anomalously cool terminator temperatures and biased abundance estimates even with existing transmission spectra of hot Jupiters. Motivated by these claims and upcoming high-quality transmission spectra we systematically explore the limitations of 1D models using synthetic and current observations. We use 1D models of varying complexity, both analytic and numerical, to revisit claims of biases when interpreting transmission spectra of hot Jupiters with inhomogeneous terminator compositions. Overall, we find the reported biases to be resulting from specific model assumptions rather than intrinsic limitations of 1D atmospheric models in retrieving current observations of asymmetric terminators. Additionally, we revise atmospheric retrievals of the hot Jupiter WASP-43b ($T_{\rm eq}=1440$ K) and the ultra-hot Jupiter WASP-103b ($T_{\rm eq}=2484$ K ) for which previous studies inferred abnormally cool atmospheric temperatures. We retrieve temperatures consistent with expectations. We note, however, that in the limit of extreme terminator inhomogeneities and high data quality some atmospheric inferences may conceivably be biased, although to a lesser extent than previously claimed. To address such cases, we implement a 2D retrieval framework for transmission spectra which allows accurate constraints on average atmospheric properties and provides insights into the spectral ranges where the imprints of atmospheric inhomogeneities are strongest. Our study highlights the need for careful considerations of model assumptions and data quality before attributing biases in retrieved estimates to unaccounted atmospheric inhomogeneities. dc.language en dc.publisher American Astronomical Society dc.subject 350 dc.subject The Solar System, Exoplanets, and Astrobiology dc.title On Atmospheric Retrievals of Exoplanets with Inhomogeneous Terminators dc.type Article dc.date.updated 2022-07-05T20:00:14Z prism.publicationName Astrophysical Journal dc.identifier.doi 10.17863/CAM.86228 dcterms.dateAccepted 2022-05-03 rioxxterms.versionofrecord 10.3847/1538-4357/ac6df1 rioxxterms.version VoR rioxxterms.licenseref.uri http://creativecommons.org/licenses/by/4.0/ dc.contributor.orcid Welbanks, L [0000-0003-0156-4564] dc.contributor.orcid Madhusudhan, N [0000-0002-4869-000X] dc.identifier.eissn 1538-4357 pubs.funder-project-id Engineering and Physical Sciences Research Council (EP/P020259/1) cam.issuedOnline 2022-07-05
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