The direct detection and detailed characterization of exoplanets using extreme adaptive optics (ExAO) is a key science case of both current and future telescopes. However, both quasi-static and residual atmospheric wavefront errors currently limit the sensitivity of this endeavour, generating “speckles” in a coronagraphic image that initially obscure any faint exoplanet(s) from detection.
I first demonstrate the current limits of exoplanet imaging using datasets taken with the Gemini Planet Imager and Subaru Coronagraphic ExAO systems. Even when using advanced post-processing algorithms, speckle evolution over time and wavelength is shown to limit the final contrasts that can be reached with current state- of-the-art instruments. A new approach is thus needed to detect fainter exoplanets below these limits.
I then illustrate a path forward to reach contrasts near the fundamental photon noise limit: fast focal plane wavefront sensing of both quasi-static and atmospheric speckles. My new method, called the Fast Atmospheric Self-coherent camera Technique (FAST), deploys new hardware and software to overcome these limitations. Looking toward the future, the contrast improvements from fast focal plane wave- front sensing techniques such as FAST are expected to play an essential role in the ground-based detection and characterization of lower mass exoplanets. / Graduate
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/11755 |
| Date | 20 May 2020 |
| Creators | Gerard, Benjamin Lionel |
| Contributors | Marois, Christian, Willis, Jon |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
| Rights | Available to the World Wide Web |
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