Detection of a high-velocity sodium feature on the ultra-hot Jupiter WASP-121 b
| Autor: | Seidel, J. V., Borsa, F., Pino, L., Ehrenreich, D., Stangret, M., Osorio, M. R. Zapatero, Palle, E., Alibert, Y., Allart, R., Bourrier, V., Di Marcantonio, P., Figueira, P., Hernandez, J. I. Gonzalez, Lillo-Box, J., Lovis, C., Martins, C. J. A. P., Mehner, A., Molaro, P., Nunes, N. J., Pepe, F., Santos, N. C., Sozzetti, A. |
|---|---|
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | A&A 673, A125 (2023) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1051/0004-6361/202245800 |
| Popis: | Ultra-hot Jupiters, with their high equilibrium temperatures and resolved spectral lines, have emerged as a perfect testbed for new analysis techniques in the study of exoplanet atmospheres. In particular, the resolved sodium doublet as a resonant line has proven a powerful indicator to probe the atmospheric structure over a wide pressure range. We explore an atmospheric origin of the observed blueshifted feature next to the sodium doublet of the ultra-hot Jupiter WASP-121~b, using a partial transit obtained with the 4-UT mode of ESPRESSO. We study its atmospheric dynamics visible across the terminator by splitting the data into mid-transit and egress. We determine that the blueshifted high-velocity absorption component is generated only during the egress part of the transit when a larger fraction of the day side of the planet is visible. For the egress data, MERC retrieves the blueshifted high-velocity absorption component as an equatorial day-to-night side wind across the evening limb, with no zonal winds visible on the morning terminator with weak evidence compared to a model with only vertical winds. For the mid-transit data, the observed line broadening is attributed to a vertical, radial wind. We attribute the equatorial day-to-night side wind over the evening terminator to a localised jet and restrain its existence between the substellar point and up to $10^\circ$ to the terminator in longitude, an opening angle of the jet of at most $60^\circ$ in latitude, and a lower boundary in altitude between [1.08, 1.15] $R_p$. Due to the partial nature of the transit, we cannot make any statements on whether the jet is truly super-rotational and one-sided or part of a symmetric day-to-night side atmospheric wind from the hotspot. Comment: 15 pages, 10 figures, 2 appendixes, accepted for publication in A&A on March 10th, 2023 |
| Databáze: | arXiv |
| Externí odkaz: |
|