tomtom · Mapping Giant Planet Formation Sites with Spectral Line Tomography

The stunning variety of physical and chemical properties of the ever-growing census of detected exoplanets is believed to arise as a consequence of their formation. Over the last decade, the advent of new facilities, first and foremost the Atacama Large Millimetre/(sub-)millimetre Array (ALMA) and the James Webb Space Telescope (JWST), has revolutionized our understanding of this process through detailed investigations of the chemical content of exoplanet atmospheres and the environments where these planets were assembled, planet-forming discs. However, a link between planetary and disc properties is still missing. The main reason is that, despite the wealth of available data, we are still fundamentally blind to the intermediate disc regions (between a few and 20 au), where the occurrence rate of giant planets—those with the best-studied atmospheric composition—peaks. In fact, while ALMA is mostly sensitive to the cold (20 K) outer (>20 au) disc regions, JWST probes only the hot (>100 K) inner (<few au) ones. Thanks to dedicated training at the Max Planck Institute for Astronomy (MPIA) and during my secondment at the Smithsonian Astrophysical Observatory (SAO), I will develop new skills to leverage the unprecedented spectral resolution of recent observations—with ALMA and ground-based IR spectrographs complementary to JWST—to reconstruct the morphology of molecular line intensity profiles able to bridge the gap between (sub)mm and current (and future, e.g., ELT) IR facilities by leveraging the disc's Keplerian rotation pattern. My results will make it possible to characterize the volatile makeup of planet-forming material in this disc region most critical for planet formation, yet still unexplored. In the longer term, my work as an MSCA fellow will lay the ground for causally connecting, for the first time, planetary to disc composition, a crucial step to unveil how planets come to be and their potential for habitability.