Cartographie moléculaire d'exoplanètes avec le télescope spatial James Webb
Hot Jupiter atmospheres, receiving extreme amounts of irradiation from their host star, enable us to study the atmospheric chemistry and dynamics of atmospheres at regimes that would otherwise be inaccessible from solar system observations. Transmission and emission spectroscopy of these atmospheres enables their characterization. However, these methods do not consider the spatial distribution of the molecular abundances, temperature profile, and clouds. Using multi-wavelength secondary eclipse mapping, it is possible to measure the spatial distribution of the atmospheric parameters. Secondary eclipse mapping has only been applied for photometric Spitzer/IRAC 8 μm observations of HD 189733 b so far. With the imminent launch of JWST, high-precision spectrophotometric observations of hot Jupiters are expected, reinforcing the need for a framework that can simulate and retrieve secondary eclipse mapping observations. We present a novel method to simulate secondary eclipse light curves for non-uniform atmospheres at multiple wavelengths, as well as a statistical method to retrieve the distribution from observations. The simulation of the multi-wavelength light curves is discretized to enable the fast computation necessary for statistical analysis of observations. We apply these methods to simulated JWST NIRSpec observations of WASP-33 b for various distributions of the water dissociation coefficient and conclude that 5 secondary eclipse observations are sufficient to constrain significant spatial variations in longitude and latitude. The application of the multi-wavelength secondary eclipse mapping to JWST will further deepen our understanding of the atmospheric dynamics processes to which hot Jupiter atmospheres are subjected.
Exoplanets Exocartography Numerical methods