| Online-Ressource |
Verfasst von: | Lampón, Manuel [VerfasserIn]  |
| López-Puertas, M. [VerfasserIn]  |
| Lara, L. M. [VerfasserIn]  |
| Sánchez López, Alejandro [VerfasserIn]  |
| Salz, M. [VerfasserIn]  |
| Czesla, Stefan [VerfasserIn]  |
| Sanz-Forcada, J. [VerfasserIn]  |
| Molaverdikhani, Karan [VerfasserIn]  |
| Alonso Floriano, Francisco J. [VerfasserIn]  |
| Nortmann, L. [VerfasserIn]  |
| Caballero, José A. [VerfasserIn]  |
| Bauer, F. F. [VerfasserIn]  |
| Pallé, Enric [VerfasserIn]  |
| Montes, D. [VerfasserIn]  |
| Quirrenbach, Andreas [VerfasserIn]  |
| Nagel, E. [VerfasserIn]  |
| Ribas, Ignasi [VerfasserIn]  |
| Reiners, Ansgar [VerfasserIn]  |
| Amado, P. J. [VerfasserIn]  |
Titel: | Modelling the He I triplet absorption at 10 830 Å in the atmosphere of HD 209458 b |
Verf.angabe: | M. Lampón, M. López-Puertas, L.M. Lara, A. Sánchez-López, M. Salz, S. Czesla, J. Sanz-Forcada, K. Molaverdikhani, F.J. Alonso-Floriano, L. Nortmann, J.A. Caballero, F.F. Bauer, E. Pallé, D. Montes, A. Quirrenbach, E. Nagel, I. Ribas, A. Reiners, and P.J. Amado |
E-Jahr: | 2020 |
Jahr: | 07 April 2020 |
Umfang: | 14 S. |
Fussnoten: | Gesehen am 20.10.2020 |
Titel Quelle: | Enthalten in: Astronomy and astrophysics |
Ort Quelle: | Les Ulis : EDP Sciences, 1969 |
Jahr Quelle: | 2020 |
Band/Heft Quelle: | 636(2020) Artikel-Nummer A13, 14 Seiten |
ISSN Quelle: | 1432-0746 |
Abstract: | HD 209458 b is an exoplanet with an upper atmosphere undergoing blow-off escape that has mainly been studied using measurements of the Ly<i>α<i/> absorption. Recently, high-resolution measurements of absorption in the He I triplet line at 10 830 Å of several exoplanets (including HD 209458 b) have been reported, creating a new opportunity to probe escaping atmospheres.<i>Aims.<i/> We aim to better understand the atmospheric regions of HD 209458 b from where the escape originates.<i>Methods.<i/> We developed a 1D hydrodynamic model with spherical symmetry for the HD 209458 b thermosphere coupled with a non-local thermodynamic model for the population of the He I triplet state. In addition, we performed high-resolution radiative transfer calculations of synthetic spectra for the helium triplet lines and compared them with the measured absorption spectrum in order to retrieve information about the atmospheric parameters.<i>Results.<i/> We find that the measured spectrum constrains the [H]/[H<sup>+<sup/>] transition altitude occurring in the range of 1.2 <i>R<i/><sub>P<sub/>-1.9 <i>R<i/><sub>P<sub/>. Hydrogen is almost fully ionised at altitudes above 2.9 <i>R<i/><sub>P<sub/>. We also find that the X-ray and extreme ultraviolet absorption takes place at effective radii from 1.16 to 1.30 <i>R<i/><sub>P<sub/>, and that the He I triplet peak density occurs at altitudes from 1.04 to 1.60 <i>R<i/><sub>P<sub/>. Additionally, the averaged mean molecular weight is confined to the 0.61-0.73 g mole<sup>−1<sup/> interval, and the thermospheric H/He ratio should be larger than 90/10, and most likely approximately 98/2. We also provide a one-to-one relationship between mass-loss rate and temperature. Based on the energy-limited escape approach and assuming heating efficiencies of 0.1-0.2, we find a mass-loss rate in the range of (0.42-1.00) ×10<sup>11<sup/> g s<sup>−1<sup/> and a corresponding temperature range of 7125-8125 K.<i>Conclusions.<i/> The analysis of the measured He I triplet absorption spectrum significantly constrains the thermospheric structure of HD 209458 b and advances our knowledge of its escaping atmosphere. |
DOI: | doi:10.1051/0004-6361/201937175 |
URL: | Bitte beachten Sie: Dies ist ein Bibliographieeintrag. Ein Volltextzugriff für Mitglieder der Universität besteht hier nur, falls für die entsprechende Zeitschrift/den entsprechenden Sammelband ein Abonnement besteht oder es sich um einen OpenAccess-Titel handelt.
Volltext ; Verlag: https://doi.org/10.1051/0004-6361/201937175 |
| Volltext: https://www.aanda.org/articles/aa/abs/2020/04/aa37175-19/aa37175-19.html |
| DOI: https://doi.org/10.1051/0004-6361/201937175 |
Datenträger: | Online-Ressource |
Sprache: | eng |
K10plus-PPN: | 1700732749 |
Verknüpfungen: | → Zeitschrift |
Modelling the He I triplet absorption at 10 830 Å in the atmosphere of HD 209458 b / Lampón, Manuel [VerfasserIn]; 07 April 2020 (Online-Ressource)