Where Is the Water? Jupiter-like C/H Ratio but Strong H 2 O Depletion Found on τ Boötis b Using SPIRou
| Autor: | Neil Cook, Charles Cadieux, Claire Moutou, David Lafrenière, J. H. C. Martins, Antoine Darveau-Bernier, Guillaume Hébrard, Stefan Pelletier, Simon Delisle, Romain Allart, Pascal Fouqué, Jean-François Donati, Björn Benneke, Caroline Piaulet, Anne Boucher, Louis-Philippe Coulombe, Étienne Artigau, René Doyon, Thomas Vandal, Eder Martioli, Xavier Delfosse |
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| Přispěvatelé: | Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), ANR-18-CE31-0019,SPlaSH,Recherche de planètes habitables avec SPIRou(2018), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Physics
010308 nuclear & particles physics Astronomy and Astrophysics Astrophysics Molecular spectroscopy 01 natural sciences Astronomical instrumentation Jupiter 13. Climate action Space and Planetary Science [SDU]Sciences of the Universe [physics] 0103 physical sciences 010303 astronomy & astrophysics ComputingMilieux_MISCELLANEOUS Astrophysics - Earth and Planetary Astrophysics |
| Zdroj: | The Astronomical Journal The Astronomical Journal, 2021, 162 (2), pp.73. ⟨10.3847/1538-3881/ac0428⟩ The Astronomical Journal, American Astronomical Society, 2021, 162 (2), pp.73. ⟨10.3847/1538-3881/ac0428⟩ |
| ISSN: | 0004-6256 1538-3881 |
| DOI: | 10.3847/1538-3881/ac0428⟩ |
| Popis: | The present-day envelope of gaseous planets is a relic of how these giant planets originated and evolved. Measuring their elemental composition therefore presents a powerful opportunity to answer long-standing questions regarding planet formation. Obtaining precise observational constraints on the elemental inventory of giant exoplanets has, however, remained challenging due to the limited simultaneous wavelength coverage of current space-based instruments. Here, we present thermal emission observations of the non-transiting hot Jupiter $\tau$ Boo b using the new wide wavelength coverage (0.95$-$2.50$\,\mu$m) and high spectral resolution ($R=70\,000$) SPIRou spectrograph. By combining a total of 20 hours of SPIRou data obtained over five nights in a full atmospheric retrieval framework designed for high-resolution data, we constrain the abundances of all the major oxygen- and carbon-bearing molecules and recover a non-inverted temperature structure using a new free-shape, nonparametric TP profile retrieval approach. We find a volume mixing ratio of log(CO)$\,\,=-2.46_{-0.29}^{+0.25}$ and a highly depleted water abundance of less than $0.0072$ times the value expected for a solar composition envelope. Combined with upper limits on the abundances of CH$_4$, CO$_2$, HCN, TiO, and C$_2$H$_2$, this results in a gas-phase C/H ratio of 5.85$_{-2.82}^{+4.44}\times\,$solar, consistent with the value of Jupiter, and an envelope C/O ratio robustly greater than 0.60, even when taking into account the oxygen that may be sequestered out of the gas-phase. Combined, the inferred super-solar C/H, O/H, and C/O ratios on $\tau$ Boo b support a formation scenario beyond the water snowline in a disk enriched in CO due to pebble drift. Comment: 27 pages, 14 figures, 3 tables, Accepted for publication in The Astronomical Journal |
| Databáze: | OpenAIRE |
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