Characterization of hot Jupiter atmospheres with Keck/KPIC

Abstract

Combined light high-resolution cross-correlation spectroscopy (HRCCS) uses cross-correlation with a model planetary atmosphere to identify/isolate spectral features that show a Doppler shift consistent with the motion of a close-in exoplanet. This technique can be used to retrieve molecular abundances and pressure-temperature profiles for hot Jupiters, offering insight into planet formation and atmospheric chemistry. HRCCS is quite sensitive to instrumental systematics, in particular shifts in wavelength solution, blaze function variation, uncorrected tellurics, and fringing. We discuss the on-sky performance of Keck/KPIC for HRCCS, with a focus on the impact of these systematic effects and mitigation approaches.