Presentation #624.04 in the session Planetary Atmospheres - Hot Jupiters.
We present a detailed analysis of the atmospheric properties of the hot Jupiter WASP-43b, utilising a set of four phase-resolved emission spectra observed by the MIRI/LRS instrument aboard the JWST as part of the Transiting Exoplanet Community Early Release Science Program. Employing a novel 2D atmospheric model and assuming a well-mixed atmosphere, we independently retrieve the volume mixing ratios of molecules by fitting the four spectra simultaneously. Our investigation leads to the first detection of NH3 in the atmosphere of a hot Jupiter using thermal emission, alongside the detections of H2O and CO and the notable non-detection of CH4. We analyse complementary emission spectra generated from HST/WFC3 and Spitzer/IRAC phase curves and find consistent abundance constraints to those obtained from the MIRI data. The chemical abundances inferred from our analysis indicate a solar composition atmosphere significantly influenced by disequilibrium chemistry. Our findings offer vital insights into the formation history of WASP-43b by simultaneously constraining the atmospheric abundances of carbon, oxygen, and nitrogen-bearing species. Leveraging MIRI eclipse mapping, we conduct additional retrievals of the MIRI dataset incorporating various latitudinal temperature distributions to retrieve the three-dimensional thermal structure of WASP-43b. Our analysis characterises the atmosphere of WASP-43b with exceptional clarity, setting a solid foundation for future observations.