Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Time-resolved absorption of six chemical species with MAROON-X points to a strong drag in the ultra-hot Jupiter TOI-1518 b

Simonnin, A. LU ; Parmentier, V. ; Wardenier, J. P. ; Chauvin, G. ; Chiavassa, A. ; N'diaye, M. ; Tan, X. ; Heidari, N. ; Prinoth, B. LU orcid and Bean, J. , et al. (2025) In Astronomy and Astrophysics 698.
Abstract

Context. Wind dynamics play a pivotal role in governing transport processes within planetary atmospheres, influencing atmospheric chemistry, cloud formation, and the overall energy budget. Understanding the strength and patterns of winds is crucial for comprehensive insights into the physics of ultra-hot-Jupiter atmospheres. Current research has proposed different mechanisms that limit wind speeds in these atmospheres. Aims. This study focuses on unraveling the wind dynamics and the chemical composition in the atmosphere of the ultra-hot Jupiter TOI-1518 b. Methods. Two transit observations using the high-resolution (Rλ a -85 000) optical (spectral coverage between 490 and 920 nm) spectrograph MAROON-X were obtained and... (More)

Context. Wind dynamics play a pivotal role in governing transport processes within planetary atmospheres, influencing atmospheric chemistry, cloud formation, and the overall energy budget. Understanding the strength and patterns of winds is crucial for comprehensive insights into the physics of ultra-hot-Jupiter atmospheres. Current research has proposed different mechanisms that limit wind speeds in these atmospheres. Aims. This study focuses on unraveling the wind dynamics and the chemical composition in the atmosphere of the ultra-hot Jupiter TOI-1518 b. Methods. Two transit observations using the high-resolution (Rλ a -85 000) optical (spectral coverage between 490 and 920 nm) spectrograph MAROON-X were obtained and analyzed to explore the chemical composition and wind dynamics using the cross-correlation techniques, global circulation models (GCMs), and atmospheric retrieval. Results. We report the detection of 14 species in the atmosphere of TOI-1518 b through cross-correlation analysis. VO was detected only with the new HyVO line list, whereas TiO was not detected. Additionally, we measured the time-varying cross-correlation trails for six different species, compared them with predictions from GCMs, and conclude that a strong drag is slowing the winds in TOI-1518 b's atmosphere (Idrag '103'104 s). We find that the trails are species dependent. Fe+ favors stronger drag than Fe, which we interpret as a sign of magnetic effects being responsible for the observed strong drag. Furthermore, we show that Ca+ probes layers above the Roche lobe, leading to a qualitatively different trail than the other species. Finally, We used a retrieval analysis to further characterize the abundances of the different species detected. Our analysis is refined thanks to the updated planetary mass of 1.83 ± 0.47 MJup we derived from new Sophie radial-velocity observations. We measure an abundance of Fe of log10 Fe = '4.88'0.76+0.63 corresponding to 0.07 to 1.62 solar enrichment. For the other elements, the retrievals appear to be biased, probably due to the different Kp/Vsys shifts between Fe and the other elements, which we demonstrate for the case of VO.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and , et al. (More)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; and (Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Planets and satellites: atmospheres, Planets and satellites: composition, Techniques: spectroscopic
in
Astronomy and Astrophysics
volume
698
article number
A314
publisher
EDP Sciences
external identifiers
  • scopus:105009631362
ISSN
0004-6361
DOI
10.1051/0004-6361/202453241
language
English
LU publication?
yes
additional info
Publisher Copyright: © The Authors 2025.
id
dcf44a88-e30a-4d45-b008-56775905f776
date added to LUP
2025-12-17 15:57:45
date last changed
2025-12-17 15:58:28
@article{dcf44a88-e30a-4d45-b008-56775905f776,
  abstract     = {{<p>Context. Wind dynamics play a pivotal role in governing transport processes within planetary atmospheres, influencing atmospheric chemistry, cloud formation, and the overall energy budget. Understanding the strength and patterns of winds is crucial for comprehensive insights into the physics of ultra-hot-Jupiter atmospheres. Current research has proposed different mechanisms that limit wind speeds in these atmospheres. Aims. This study focuses on unraveling the wind dynamics and the chemical composition in the atmosphere of the ultra-hot Jupiter TOI-1518 b. Methods. Two transit observations using the high-resolution (R<sub>λ</sub> a -85 000) optical (spectral coverage between 490 and 920 nm) spectrograph MAROON-X were obtained and analyzed to explore the chemical composition and wind dynamics using the cross-correlation techniques, global circulation models (GCMs), and atmospheric retrieval. Results. We report the detection of 14 species in the atmosphere of TOI-1518 b through cross-correlation analysis. VO was detected only with the new HyVO line list, whereas TiO was not detected. Additionally, we measured the time-varying cross-correlation trails for six different species, compared them with predictions from GCMs, and conclude that a strong drag is slowing the winds in TOI-1518 b's atmosphere (I<sub>drag</sub> '10<sup>3</sup>'10<sup>4</sup> s). We find that the trails are species dependent. Fe+ favors stronger drag than Fe, which we interpret as a sign of magnetic effects being responsible for the observed strong drag. Furthermore, we show that Ca+ probes layers above the Roche lobe, leading to a qualitatively different trail than the other species. Finally, We used a retrieval analysis to further characterize the abundances of the different species detected. Our analysis is refined thanks to the updated planetary mass of 1.83 ± 0.47 M<sub>Jup</sub> we derived from new Sophie radial-velocity observations. We measure an abundance of Fe of log<sub>10</sub> Fe = '4.88<sub>'0.76</sub><sup>+0.63</sup> corresponding to 0.07 to 1.62 solar enrichment. For the other elements, the retrievals appear to be biased, probably due to the different K<sub>p</sub>/V<sub>sys</sub> shifts between Fe and the other elements, which we demonstrate for the case of VO.</p>}},
  author       = {{Simonnin, A. and Parmentier, V. and Wardenier, J. P. and Chauvin, G. and Chiavassa, A. and N'diaye, M. and Tan, X. and Heidari, N. and Prinoth, B. and Bean, J. and Hébrard, G. and Line, M. and Kitzmann, D. and Kasper, D. and Pelletier, S. and Seidel, J. V. and Seifhart, A. and Benneke, B. and Bonfils, X. and Brogi, M. and Désert, J. M. and Gandhi, S. and Hammond, M. and Lee, E. K.H. and Moutou, C. and Palma-Bifani, P. and Pino, L. and Rauscher, E. and Weiner Mansfield, M. and Serrano Bell, J. and Smith, P.}},
  issn         = {{0004-6361}},
  keywords     = {{Planets and satellites: atmospheres; Planets and satellites: composition; Techniques: spectroscopic}},
  language     = {{eng}},
  month        = {{06}},
  publisher    = {{EDP Sciences}},
  series       = {{Astronomy and Astrophysics}},
  title        = {{Time-resolved absorption of six chemical species with MAROON-X points to a strong drag in the ultra-hot Jupiter TOI-1518 b}},
  url          = {{http://dx.doi.org/10.1051/0004-6361/202453241}},
  doi          = {{10.1051/0004-6361/202453241}},
  volume       = {{698}},
  year         = {{2025}},
}