Abstract:
Exoplanet science encompasses one of the biggest existential questions: Are we alone in the universe? One promising approach to address this question is atmospheric spectroscopy, which provides a window into the composition and structure of exoplanet atmospheres. The recent launch of the James Webb Space Telescope and upcoming missions like Ariel and Twinkle provide a strong incentive for characterizing these distant worlds, with research into super-Earth and sub-Neptune exoplanets becoming increasingly popular because of their potential to reveal important clues into the origin and prevalence of life in the universe. However, the link between retrieved spectra and the underlying physical processes driving atmospheric enrichment is not well understood. Understanding these processes is crucial to interpret data and distinguish between biotic and abiotic spectral signatures. In this talk, I will explore the enrichment mechanisms leading to super-solar metallicities in super-Earth and sub-Neptune exoplanet atmospheres. The enrichment mechanisms are: (1) direct accretion of enriched nebular gas, (2) chemical processing between the planetary nucleus and the atmosphere, (3) preferential atmospheric escape, (4) geological outgassing, (5) late accretion of planetesimals, and (6) core erosion. My previous research has addressed the first three mechanisms, and my future work will explore the remaining three and identify population-level enrichment trends.
