Non-LTE Spectroscopy of Atmospheres of Exoplanets

Thousands of exoplanets have been discovered in the recent years, many of them are exposed to high temperatures being found very close to the parent star and thus possessing very complex atmospheric properties. For example, some of these objects are believed to be losing their atmospheres (Cancri 55 e), while others are shown to produce super-rotating, high-speed jets (HD 209458b). Atmospheric modelling and remote sensing of atmospheres affected by these non-equilibrium processes which have not been incorporated into traditional radiative transfer calculations. The so-called "non-LTE" (non-local thermal equilibrium) processes are known to play important role in the atmosphere of Earth and other solar planets and thus are expected to have impact on the spectroscopy of exoplanets. The goal of this PhD project to study non-LTE spectroscopic effects of exoplanetary atmospheres and how thy impact characterisation of their properties, such as composition, temperature and dynamics. As part of the project, new computational models for describing non-LTE infrared emission and absorption in atmospheres of exoplanets will be developed and incorporated into existing radiative transfer algorithms. The main species to be studied include H2O, CO2, CH4, CO2, C2H2, HCN and NH3. The non-LTE spectroscopic signatures of these molecules will be predicted and used for interpretation of actual spectra of exoplanets.