Ultra-high resolution spectroscopy from ground and space for exoplanet atmosphere characterization

Up to date over 4,000 known exoplanets have been detected. Spectroscopy during planet transits in front of host stars is starting to shed light on the diversity of atmospheres and planets. Earth-like rocky planets are intriguing to search for biosignatures such as H₂O, CH₄, O₃ and O₂. Detecting and resolving these very narrow absorption lines from low-pressure atmospheric layers requires extreme spectroscopic resolution, also to distinguish telluric and exoplanet signals. Recent studies indicate upcoming Extremely Large Telescopes combined with spectral resolutions of R~400,000 are ideal to detect O₂ in earth analogs from ground. To boost typical high-resolution spectrographs (R~100,000) to that level, novel Fabry Perot Interferometer-based concepts have been developed. Prototypes achieve a spectral resolution of approximately 500,000 with high throughput. I will present first on-sky results from our prototype and discuss the future of this technology for exoplanet characterization from ground and space.