Publication:
Detection of iron emission lines and a temperature inversion on the dayside of the ultra-hot Jupiter KELT-20b

Loading...
Thumbnail Image
Full text at PDC
Publication Date
2022-02-25
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
EDP Sciencies
Citations
Google Scholar
Research Projects
Organizational Units
Journal Issue
Abstract
Ultra-hot Jupiters (UHJs) are gas giants with very high equilibrium temperatures. In recent years, multiple chemical species, including various atoms and ions, have been discovered in their atmospheres. Most of these observations have been performed with transmission spectroscopy, although UHJs are also ideal targets for emission spectroscopy due to their strong thermal radiation. We present highresolution thermal emission spectroscopy of the transiting UHJ KELT-20b/MASCARA-2b. The observation was performed with the CARMENES spectrograph at orbital phases before and after the secondary eclipse. We detected atomic Fe using the cross-correlation technique. The detected Fe lines are in emission, which unambiguously indicates a temperature inversion on the dayside hemisphere. We furthermore retrieved the temperature structure with the detected Fe lines. The result shows that the atmosphere has a strong temperature inversion with a temperature of 4900 +/- 700 K and a pressure of 10-4.8(-1.1)(+1.0) bar at the upper layer of the inversion. A joint retrieval of the CARMENES data and the TESS secondary eclipse data returns a temperature of 2550(-250)(+150) K and a pressure of 10(-1.5-0.6+0.7 )bar at the lower layer of the temperature inversion. The detection of such a strong temperature inversion is consistent with theoretical simulations that predict an inversion layer on the dayside of UHJs. The joint retrieval of the CARMENES and TESS data demonstrates the power of combing high-resolution emission spectroscopy with secondary eclipse photometry in characterizing atmospheric temperature structures.
Description
Ā© ESO 2022. ArtĆ­culo firmado por 28 autores. We thank the referee for the useful comments. F.Y. acknowledges the support of the DFG Research Unit FOR2544 "Blue Planets around Red Stars" (RE 1664/21-1). CARMENES is an instrument for the Centro AstronĆ³mico Hispano-AlemĆ”n (CAHA) at Calar Alto (Almeria, Spain), operated jointly by the Junta de AndalucĆ­a and the Instituto de AstrofĆ­sica de AndalucĆ­a (CSIC). CARMENES was funded by the Max-Planck-Gesellschaft (MPG), the Consejo Superior de Investigaciones CientĆ­ficas (CSIC), the Ministerio de EconomĆ­a y Competitividad (MINECO) and the European Regional Development Fund (ERDF) through projects FICTS-2011-02, ICTS-2017-07-CAHA-4, and CAHA16-CE-3978, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de AstrofĆ­sica de AndalucĆ­a, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Institut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de AstrofĆ­sica de Canarias, Hamburger Sternwarte, Centro de AstrobiologĆ­a and Centro AstronĆ³mico Hispano-AlemĆ”n), with additional contributions by the MINECO, the Deutsche Forschungsgemeinschaft through the Major Research Instrumentation Programme and Research Unit FOR2544 "Blue Planets around Red Stars", the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, and by the Junta de Andalucia. Based on data from the CARMENES data archive at CAB (CSIC-INTA). We acknowledge financial support from the Agencia Estatal de InvestigaciĆ³n of the Ministerio de Ciencia, InnovaciĆ³n y Universidades and the ERDF through projects PID2019-109522GB-C51/2/3/4, PGC2018-098153-B-C33, AYA2016-79425-C3-1/2/3-P, ESP2016-80435-C2-1-R and the Centre of Excellence "Severo Ochoa" and "MarĆ­a de Maeztu" awards to the Instituto de AstrofĆ­sica de Canarias (SEV-2015-0548), Instituto de AstrofĆ­sica de AndalucĆ­a (SEV-2017-0709), and Centro de AstrobiologĆ­a (MDM-2017-0737), and the Generalitat de Catalunya/CERCA programme. T.H. and P.M. acknowledge support from the European Research Council under the Horizon 2020 Framework Program via the ERC Advanced Grant Origins 83 24 28. N.C. and A.S.L. acknowledge funding from the European Research Council under the European Union's Horizon 2020 research and innovation program under grant agreement no. 694513.
UCM subjects
Unesco subjects
Keywords
Citation
Collections