Characterizing Exoplanet Atmospheres: From Lightcurve Observations to Radiativetransfer Modeling
Abstract
Multiwavelength transit and secondaryeclipse lightcurve observations are some of the most powerful techniques to probe the thermochemical properties of exoplanets. Although the large planettostar brightness contrast and few available spectral bands produce data with low signaltonoise ratios, a Bayesian approach can robustly reveal what constraints we can set, without overinterpreting the data. Here I performed an endtoend analysis of transiting exoplanet data. I analyzed spacetelescope data for three planets to characterize their atmospheres and refine their orbits, investigated correlated noise estimators, and contributed to the development of the respective dataanalysis pipelines. Chapters 2 and 3 describe the Photometry for Orbits, Eclipses and Transits (POET) pipeline to model Spitzer Space Telescope light curves, applied to secondaryeclipse observations of the Jupitersized planets WASP8b and TrES1. Chapter 4 studies commonly used correlatednoise estimators for exoplanet lightcurve modeling, time averaging, residual permutations, and wavelet likelihood, and assesses their applicability and limitations to estimate parameters uncertainties. Chapter 5 describes the opensource Bayesian Atmospheric Radiative Transfer (BART) code to characterize exoplanet atmospheres. BART combines a thermochemicalequilibrium code, a onedimensional linebyline radiativetransfer code, and the Multicore Markovchain Monte Carlo statistical module to constrains the atmospheric temperature and chemicalabundance profiles of exoplanets. I applied the BART code to the Hubble and Spitzer Space Telescope transit observations of the Neptunesized planet HATP11b. BART finds an atmosphere enhanced in heavy elements, constraining the water abundance to ~100 times that of the solar abundance.
 Publication:

arXiv eprints
 Pub Date:
 April 2016
 arXiv:
 arXiv:1604.01320
 Bibcode:
 2016arXiv160401320C
 Keywords:

 Astrophysics  Earth and Planetary Astrophysics
 EPrint:
 Ph.D. Dissertation