Characterization and retrieval of atmospheric parameters of terrestrial extrasolar planets around cool host stars

• Applicants: Professorin Dr. Heike Rauer; Dr. Franz Schreier
• Subject Area: Astrophysics and Astronomy
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 282760199

• Final Report Year: 2021

Final Report Abstract

Regarding the 1D-TERRA model, this project has enabled the development of a world-class atmospheric photochemical module for use in exoplanetary science over a wide range of atmospheric compositions. The new chemical code was applied as part of this project to some select, habitable zone exoplanets and could be used in a first study to constrain atmospheric composition comparing with newly emerging data. Regarding atmospheric radiative transfer modeling we have used Earth observations for a thorough validation of our line-by-line code GARLIC and for an assessment of the importance and detectability of molecular species in infrared transmission spectra. For the retrieval of Earth-like exoplanetary temperature profiles from thermal infrared emission spectra we have developed a novel function expansion technique and used a standard nonlinear least squares solver in combination with our line-by-line forward model.

Publications

• Comments on the Voigt function implementation in the Astropy and SpectraPlot.com packages. JQSRT, 213:13–16, 2018
  Schreier, Franz
  
• New insights into cosmic ray induced biosignature chemistry in Earth-like atmospheres. APJ, 863(1):6, 2018
  Scheucher, Markus; Grenfell, J. L.; Wunderlich, F.; Godolt, M.; Schreier, F. & Rauer, H.
  
• The Voigt and complex error function: Humlicek’s rational approximation generalized. MNRAS, 479(3):3068–3075, 2018
  Schreier, Franz
  
• Transmission spectroscopy with the ACE-FTS infrared spectral atlas of Earth: A model validation and feasibility study. Molec. Astrophysics, 11:1–22, 2018
  Schreier, Franz; Städt, Steffen; Hedelt, Pascal & Godolt, Mareike
  
• Detectability of atmospheric features of Earth-like planets in the habitable zone around M-dwarfs. A & A, 624:A49, 2019
  Wunderlich, Fabian; Godolt, Mareike; Grenfell, John Lee; Städt, Steffen; Smith, Alexis M. S.; Gebauer, Stefanie; Schreier, Franz; Hedelt, Pascal & Rauer, Heike
  
• Consistently simulating a wide range of atmospheric scenarios for K2-18b with a flexible radiative transfer module. APJ, 898(1):44, 2020
  Scheucher, Markus; Wunderlich, F.; Grenfell, J. L.; Godolt, M.; Schreier, F.; Kappel, D.; Haus, R.; Herbst, K. & Rauer, H.
  
• Distinguishing between wet and dry atmospheres of TRAPPIST-1 e and f. APJ, 901:126, 2020
  Wunderlich, Fabian; Scheucher, Markus; Godolt, M.; Grenfell, J. L.; Schreier, F.; Schneider, P. C.; Wilson, D. J.; Sánchez-López, A.; López-Puertas, M. & Rauer, H.
  
• Possible atmospheric diversity of low mass exoplanets – some central aspects. Space Science Reviews, 216 (5), July 2020
  Grenfell, John Lee; Leconte, Jeremy; Forget, François; Godolt, Mareike; Carrión-González, Óscar; Noack, Lena; Tian, Feng; Rauer, Heike; Gaillard, Fabrice; Bolmont, Émeline; Charnay, Benjamin & Turbet, Martin
  
• SVEEEETIES – singular vector expansion to estimate Earth-like exoplanet temperatures from infrared emission spectra. A & A, 633:A156, 2020
  Schreier, F.; Städt, S.; Wunderlich, F.; Godolt, M. & Grenfell, J. L.
  
• Detectability of biosignatures on LHS1140b, Dec. 2020
  Wunderlich, Fabian; Scheucher, Markus; Grenfell, John Lee; Schreier, Franz; Sousa-Silva, Clara; Godolt, Mareike & Rauer, Heike