Revealing Unique Exoplanet Atmospheres with Multi-Instrument Space Telescope Transit and Eclipse Spectroscopy

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dc.contributor.advisorDeming, Drakeen_US
dc.contributor.authorSheppard, Kyle Benensohnen_US
dc.contributor.departmentAstronomyen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2022-02-04T06:30:45Z
dc.date.available2022-02-04T06:30:45Z
dc.date.issued2021en_US
dc.description.abstractAtmospheres act as windows into their host planets, containing measurable information on their planets' chemistry, climate, and atmospheric physics. The bulk properties of planets outside of the Solar System (exoplanets) prove to be much more varied than the Solar System, allowing the ability to test atmospheric models over a range of temperatures, radii, and host star properties. Modeling and observing exoplanet atmospheres provides a better understanding of both atmospheric processes and planetary diversity, and it places the Solar System in a greater context to understand how unique it is, if at all. I take a broad approach, analyzing both transit and emission spectroscopy of 5 exoplanets populating the edges of parameter space, ranging from cool, Earth-sized planets (T$\sim$500K, R=0.8\rearth{}) up to massive, ultra-hot Jupiters (T$\sim$2500K, M=10\mjup{}). I use my publicly available, open source Python 3 analysis pipeline \texttt{DEFLATE} to process telescope data and produce verifiable spectra. I then retrieve atmospheric properties using a forward model + Bayesian sampler retrieval tool, exploring how both inter- and intra- modeling assumptions impact results. I retrieve unexpected atmospheres, including: evidence of stellar activity mimicking water vapor features in two terrestrial planets in the multi-planet L9859 system; evidence of a clear atmosphere and a superstellar atmospheric metallicity and water abundance ($5\sigma$ detection) in the hot Jupiter HAT-P-41b (R=1.65\rjup{}, T$_{\textrm{eq}}$=1950~K); a potentially non-TiO driven thermal inversion and a photometric CO detection ($6\sigma$) in the ultrahot Jupiter WASP-18b; and a water absorption feature ($2.8\sigma$) and non-inverted T-P profile in the water-dissociation-vulnerable hot Jupiter WASP-19b (R=1.4\rjup{}, T$_{\textrm{eq}}$=2120~K). Overall, these results expand already extensive diversity of exoplanet atmospheres.en_US
dc.identifierhttps://doi.org/10.13016/kkgp-cvqz
dc.identifier.urihttp://hdl.handle.net/1903/28397
dc.language.isoenen_US
dc.subject.pqcontrolledAstrophysicsen_US
dc.subject.pqcontrolledAstronomyen_US
dc.subject.pqcontrolledAtmospheric sciencesen_US
dc.subject.pquncontrolledatmospheresen_US
dc.subject.pquncontrolledbayesianen_US
dc.subject.pquncontrolledexoplanetsen_US
dc.subject.pquncontrolledplanetsen_US
dc.subject.pquncontrolledretrievalen_US
dc.titleRevealing Unique Exoplanet Atmospheres with Multi-Instrument Space Telescope Transit and Eclipse Spectroscopyen_US
dc.typeDissertationen_US

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