paper

Simulating reflected light coronagraphy of Earth-like exoplanets with a large IR/O/UV space telescope: impact and calibration of smooth exozodiacal dust

arXiv:2210.03098 · doi:10.3847/1538-3881/ac97eb

Abstract

Observing Earth-like exoplanets orbiting within the habitable zone of Sun-like stars and studying their atmospheres in reflected starlight requires contrasts of in the visible. At such high contrast, starlight reflected by exozodiacal dust is expected to be a significant source of contamination. Here, we present high-fidelity simulations of coronagraphic observations of a synthetic Solar System located at a distance of 10 pc and observed with a 12 m and an 8 m circumscribed aperture diameter space telescope operating at 500 nm wavelength. We explore different techniques to subtract the exozodi and stellar speckles from the simulated images in the face-on, the 30 deg inclined, and the 60 deg inclined case and quantify the remaining systematic noise as a function of the exozodiacal dust level of the system. We find that in the face-on case, the exozodi can be subtracted down to the photon noise limit for exozodi levels up to zodi using a simple toy model for the exozodiacal disk, whereas in the 60 deg inclined case this only works up to zodi. We also investigate the impact of larger wavefront errors and larger system distance, finding that while the former have no significant impact, the latter has a strong (negative) impact. Ultimately, we derive a penalty factor as a function of the exozodi level and system inclination that should be considered in exoplanet yield studies as a realistic estimate for the excess systematic noise from the exozodi.

20 pages, 9 figures, accepted for publication in AJ

References in corpus (5)

Simulating reflected light coronagraphy of Earth-like exoplanets with a large IR/O/UV space telescope: impact and calibration of smooth exozodiacal dust · wovepaper