Spectroscopic characterization of the atmosphere of potentially habitable planets: GL 581 d as a model case study
Résumé
The spectral characterization of potentially habitable planets is a major task for the exoplanet community and of prime interest for the search of extraterrestrial biospheres. Currently, one such potentially habitable planet is known outside the solar system, namely GL 581d. Based on different model atmospheres of GL 581d and resulting synthetic spectra, we will show how the possible investigation of potentially habitable planets could be used to infer atmospheric and surface conditions. In the considered case of GL 581d-like planets, we find that the presence of an atmosphere could be inferred from broad absorption bands of water and carbon dioxide in the spectra. The characterization of surface conditions and distinguishing different atmospheric scenarios is however difficult. A very interesting challenge is the possibility of a false-positive detection of so-called biomarkers such as ozone in the spectra due to the presence of carbon dioxide absorption bands close to the position of the main ozone band.