Thinkshop 2022: High-resolution spectroscopy for exoplanet atmospheres and biomarkers

Retrievals on high spectral resolution exoplanet observations have been recently made possible, allowing us now to place robust, quantitative constraints on their atmospheres in unprecedented detail. High resolution data can also be combined with low resolution, space-based data in retrievals, probing a wider range of altitudes and incorporating continuum information otherwise lost through detrending methods common in high resolution spectroscopy. We present retrieval results of combined observations of a benchmark hot Jupiter WASP-77A b, combining multiple nights taken with the IGRINS instrument on Gemini South (R~45,000), data from WFC3 on the Hubble Space Telescope (R~100), and IRAC/Spitzer photometry. We report a slightly superstellar C/O ratio and a substellar metallicity, indicative of diverse formation pathways for hot Jupiters.