Probing exoplanet formation with moderate resolution spectroscopy

Moderate to high-resolution spectroscopy can resolve molecular features in exoplanet atmospheres and therefore allows precise measurements of atmospheric composition. Identifying trends in the present day composition of exoplanets, such as metallicity or carbon to oxygen ratio, can then inform their formation pathways.With this goal in mind, we have been building a library of moderate resolution spectra of directly imaged planets with Keck/OSIRIS and in the near future with JWST/NIRSpec. I will show our latest results of our survey including the HR 8799 system and Kap And b for example.

Additionally, higher-resolution integral field spectroscopy is a powerful tool for planet detection. It is virtually insensitive to the speckle noise from the host star, which is the limiting factor for high-contrast instruments at small separations (<0.3”). We are demonstrating the power of this technique with a pilot survey of nearby star forming regions with Keck/OSIRIS. We also show that JWST/NIRSpec will likely be a game changer in this field and enable the first direct detections of older and cooler gas giants similar to Jupiter.