Romain Allart obtained his PhD at the University of Geneva, where he worked on the study of exoplanetary atmospheres at high spectral resolution. During his thesis, he used transmission spectroscopy with different atmospheric tracers to study the different layers composing exoplanetary atmospheres. He first showed the potential of the helium triplet in the near infrared as a tracer of the upper atmosphere. Then, by searching for the presence of water vapour in the visible with the ESPRESSO spectrograph, he was able to constrain the altitude of clouds in the atmosphere of exoplanets by combining high-resolution data with low-resolution data from the Hubble Space Telescope.
At the Université de Montréal, Romain continues his work at high spectral resolution using SPIRou and NIRPS data while combining them with future low-resolution observations from the James Webb Space Telescope. The study of different atmospheric tracers at different spectral resolutions will allow astronomers to have a comprehensive view of the composition of the atmospheres of exoplanets but also to understand their formation and evolution.
Also, Romain’s knowledge of different high-resolution spectrographs provides support for the extraction of NIRPS data and the improvement of telluric correction.