Structures Of Dust and gAs (SODA): Constraining the innermost dust properties of II Zw96 with JWST observations of H2O and CO
Astronomy & Astrophysics EDP Sciences 682 (2024) l5
Sulfur dioxide in the mid-infrared transmission spectrum of WASP-39b.
Nature 626:8001 (2024) 979-983
Abstract:
The recent inference of sulfur dioxide (SO2) in the atmosphere of the hot (approximately 1,100 K), Saturn-mass exoplanet WASP-39b from near-infrared JWST observations1-3 suggests that photochemistry is a key process in high-temperature exoplanet atmospheres4. This is because of the low (<1 ppb) abundance of SO2 under thermochemical equilibrium compared with that produced from the photochemistry of H2O and H2S (1-10 ppm)4-9. However, the SO2 inference was made from a single, small molecular feature in the transmission spectrum of WASP-39b at 4.05 μm and, therefore, the detection of other SO2 absorption bands at different wavelengths is needed to better constrain the SO2 abundance. Here we report the detection of SO2 spectral features at 7.7 and 8.5 μm in the 5-12-μm transmission spectrum of WASP-39b measured by the JWST Mid-Infrared Instrument (MIRI) Low Resolution Spectrometer (LRS)10. Our observations suggest an abundance of SO2 of 0.5-25 ppm (1σ range), consistent with previous findings4. As well as SO2, we find broad water-vapour absorption features, as well as an unexplained decrease in the transit depth at wavelengths longer than 10 μm. Fitting the spectrum with a grid of atmospheric forward models, we derive an atmospheric heavy-element content (metallicity) for WASP-39b of approximately 7.1-8.0 times solar and demonstrate that photochemistry shapes the spectra of WASP-39b across a broad wavelength range.Behind the mask: can HARMONI@ELT detect biosignatures in the reflected light of Proxima b?
Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 528:2 (2024) 3509-3522
Near-infrared transmission spectroscopy of HAT-P-18 b with NIRISS: Disentangling planetary and stellar features in the era of JWST
Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 528:2 (2024) 3354-3377
Modelling stellar variability in archival HARPS data: I - rotation and activity properties with multi-dimensional Gaussian processes
Monthly Notices of the Royal Astronomical Society Oxford University Press 528:4 (2024) 5511-5527