Abstract

In recent years, ground-based high-resolution spectroscopy has become an invaluable tool to characterise the atmospheres of exoplanets. It has the ability of resolving molecular bands into the individual lines, and of directly detecting the changing radial velocity of close-in planets through cross-correlation with template spectra. High resolution spectroscopy delivers robust detections of atomic and molecular species in transmission and dayside spectra of transiting and non-transiting hot Jupiters. In addition, it allows us to measure planet rotation and winds. With the E-ELT, this technique will be potentially applicable to temperate planets orbiting M-dwarfs to look for biomarkers. I will review the state of the art of the method and explain how the community is working to achieve a number of key improvements – both observational and in the modelling – crucial to enable frontier exoplanet science in the next decade. These include the joint analysis of high-resolution and low-resolution spectra, and the combination of high contrast imaging and high-resolution spectroscopy.