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Thermal dependency of CO2 VUV absorption cross section and application to warm exoplanetary atmospheres

Authors :
Venot, O.
Bénilan, Yves
Fray, Nicolas
Gazeau, Marie-Claire
Montmessin, Franck
Lefèvre, Franck
Bahrini, C.
Es-Sebbar, Et-Touhami
Schwell, Martin
Hébrard, Eric
Lefevre, M.
Waldmann, I. P.
Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583))
Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)
IMPEC - LATMOS
Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS)
Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)
STRATO - LATMOS
School of Physics and Astronomy [Exeter]
University of Exeter
Department of Physics and Astronomy [UCL London]
University College of London [London] (UCL)
Laboratoire inter-universitaire des systèmes atmosphèriques ( LISA )
Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Université Paris-Est Créteil Val-de-Marne - Paris 12 ( UPEC UP12 ) -Centre National de la Recherche Scientifique ( CNRS )
Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS )
Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS )
SHTI - LATMOS
University College of London [London] ( UCL )
Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)
PLANETO - LATMOS
Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Source :
European Planetary Science Congress 2017, European Planetary Science Congress 2017, Sep 2017, Riga, Latvia. pp.EPSC2017-42, European Planetary Science Congress 2017, Sep 2017, Riga, Latvia. 11, pp.EPSC2017-42, 2017, EPSC abstracts
Publication Year :
2017
Publisher :
HAL CCSD, 2017.

Abstract

International audience; Most of exoplanets detected so far have atmospheric temperatures significantly higher than 300 K. These exoplanets are often close to their star and thus receive an intense UV photons flux, triggering important pho-todissociation processes. However, the temperature dependency of VUV absorption cross sections, which are essential data to model photolyses in atmospheric models, are barely known. Thus, by lack of appropriate data, absorption cross sections at room temperature are used in photochemical models of extrasolar planets , leading to a non-measurable uncertainty. With the future space-or ground-based telescopes that will be developed in the coming years (JWST, E-ELT.. .) investigating these research fields becomes urgent [1]. In this context, we quantified the temperature dependency of the VUV absorption cross section of carbon dioxide (CO 2). We performed experimental measurements on the range (115-230 nm) between 150 and 800 K. The absorption cross section of CO 2 increases with the temperature (Fig. 1). At 200 nm, there are more than four orders of magnitude between the one at 300 K and the one at 800 K. We also determined a parametrisation to calculate the continuum of the absorption cross section on this wavelength range. We used these new data in our photo-thermochemical model for exoplanets [2] and studied the impact on the results (photolyses rates and chemical composition) as well as on the observables (synthetic transmission spectra) [3, 4]. We will present these experimental results and their consequences on the modelling of exo-planet atmospheres.

Details

Language :
English
Database :
OpenAIRE
Journal :
European Planetary Science Congress 2017, European Planetary Science Congress 2017, Sep 2017, Riga, Latvia. pp.EPSC2017-42, European Planetary Science Congress 2017, Sep 2017, Riga, Latvia. 11, pp.EPSC2017-42, 2017, EPSC abstracts
Accession number :
edsair.dedup.wf.001..6bf4f0cb979381129deae8d7353fdd71