Emission Spectra Modeling and Parameter Retrieval for Exoplanet Atmospheres
Abstract
The current state of the art for exoplanet atmospheric modeling and retrieval reasonably predicts the contribution of Rayleigh scattering, reflection, and molecular absorption given Hubble Space Telescope (HST) or Spitzer Space Telescope data, using a two-stream approximation of the radiative transfer equation. However, the next generation of observations - such as that from the James Webb Space Telescope (JWST) and the Atmospheric Remote-Sensing Infrared Exoplanet Large-Survey (ARIEL) - will improve the quality and the coverage of the spectra probing exoplanet atmospheres. Thus, the complexity of models needed to interpret them will have to grow. In this project, we use a modified version of DISORT, a monochromatic, unpolarized radiative transfer code, to write a multi-stream emission modeling and retrieval code that accounts for scattering phase functions beyond the Rayleigh regime, a parametrized thermal profile, and both molecular and collision-induced absorption. We then use emission spectra from HST WFC3 to perform a full atmospheric content recovery of WASP-121b, an extremely irradiated Hot Jupiter. To accomplish this, we create a grid of pre-computed models and interpolate over them in order to reduce computational costs while still preserving the robustness of our modeling procedure. We then run an MCMC algorithm on the interpolated function to find the best fit model to our given data set. We include a study of any correlations between parameters, and a discussion of the impact of our research on future missions.
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23517316M