Quantifying thermal water dissociation in the dayside photosphere of WASP-121 b using NIRPS
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866918151260733440 |
|---|---|
| author | Bazinet, Luc Allart, Romain Benneke, Björn Pelletier, Stefan Wardenier, Joost P. Cook, Neil J. Forveille, Thierry Nielsen, Louise D. Moulla, Khaled Al Artigau, Étienne Baron, Frédérique Barros, Susana C. C. Bonfils, Xavier Bouchy, François Bryan, Marta Martins, Bruno L. Canto Cloutier, Ryan Cowan, Nicolas B. de Freitas, Daniel Brito De Medeiros, Jose Renan Delfosse, Xavier Doyon, René Dumusque, Xavier Ehrenreich, David Hernández, Jonay I. González Lafrenière, David Leão, Izan de Castro Lovis, Christophe Malo, Lison Melo, Claudio Mignon, Lucile Mordasini, Christoph Pepe, Francesco Rebolo, Rafael Rowe, Jason Santos, Nuno C. Ségransan, Damien Mascareño, Alejandro Suárez Udry, Stéphane Valencia, Diana Wade, Gregg Abreu, Manuel Aguiar, José L. A. Allain, Guillaume Arial, Tomy Auger, Hugues Blind, Nicolas Bohlender, David Boucher, Anne Bourrier, Vincent Bovay, Sébastien Broeg, Christopher Brousseau, Denis Cabral, Alexandre Cadieux, Charles Carmona, Andres Challita, Zalpha Chazelas, Bruno Coelho, João Cointepas, Marion Silva, Ana Rita Costa Coulombe, Louis-Philippe Cristo, Eduardo Darveau-Bernier, Antoine Dauplaise, Laurie Gomes, Roseane de Lima Fontinele, Dasaev O. Frensch, Yolanda G. C. Genest, Frédéric Genolet, Ludovic Témich, Félix Gracia Hernandez, Olivier Hoeijmakers, H. Jens Hubin, Norbert Jayawardhana, Ray Käufl, Hans-Ulrich Kerley, Dan Kolb, Johann Krishnamurthy, Vigneshwaran Kung, Benjamin Lamontagne, Pierrot Lim, Olivia Curto, Gaspare Lo Rasilla, José Luis Martins, Allan M. Matthews, Jaymie Mayer, Jean-Sébastien Messias, Yuri S. Metchev, Stan Mounzer, Dany Nari, Nicola Osborn, Ares Ouellet, Mathieu Parc, Léna Pasquini, Luca Peroux, Céline Piaulet-Ghorayeb, Caroline Pompei, Emanuela Poulin-Girard, Anne-Sophie Reshetov, Vladimir Saint-Antoine, Jonathan Sarajlic, Mirsad Schnell, Robin Segovia, Alex Seidel, Julia Silber, Armin Sinclair, Peter Sordet, Michael Sosnowska, Danuta Srivastava, Avidaan Stefanov, Atanas K. Teixeira, Márcio A. Thibault, Simon Vallée, Philippe Vandal, Thomas Vaulato, Valentina Wehbe, Bachar Weisserman, Drew Wevers, Ivan Wildi, François Yariv, Vincent Zins, Gérard |
| author_facet | Bazinet, Luc Allart, Romain Benneke, Björn Pelletier, Stefan Wardenier, Joost P. Cook, Neil J. Forveille, Thierry Nielsen, Louise D. Moulla, Khaled Al Artigau, Étienne Baron, Frédérique Barros, Susana C. C. Bonfils, Xavier Bouchy, François Bryan, Marta Martins, Bruno L. Canto Cloutier, Ryan Cowan, Nicolas B. de Freitas, Daniel Brito De Medeiros, Jose Renan Delfosse, Xavier Doyon, René Dumusque, Xavier Ehrenreich, David Hernández, Jonay I. González Lafrenière, David Leão, Izan de Castro Lovis, Christophe Malo, Lison Melo, Claudio Mignon, Lucile Mordasini, Christoph Pepe, Francesco Rebolo, Rafael Rowe, Jason Santos, Nuno C. Ségransan, Damien Mascareño, Alejandro Suárez Udry, Stéphane Valencia, Diana Wade, Gregg Abreu, Manuel Aguiar, José L. A. Allain, Guillaume Arial, Tomy Auger, Hugues Blind, Nicolas Bohlender, David Boucher, Anne Bourrier, Vincent Bovay, Sébastien Broeg, Christopher Brousseau, Denis Cabral, Alexandre Cadieux, Charles Carmona, Andres Challita, Zalpha Chazelas, Bruno Coelho, João Cointepas, Marion Silva, Ana Rita Costa Coulombe, Louis-Philippe Cristo, Eduardo Darveau-Bernier, Antoine Dauplaise, Laurie Gomes, Roseane de Lima Fontinele, Dasaev O. Frensch, Yolanda G. C. Genest, Frédéric Genolet, Ludovic Témich, Félix Gracia Hernandez, Olivier Hoeijmakers, H. Jens Hubin, Norbert Jayawardhana, Ray Käufl, Hans-Ulrich Kerley, Dan Kolb, Johann Krishnamurthy, Vigneshwaran Kung, Benjamin Lamontagne, Pierrot Lim, Olivia Curto, Gaspare Lo Rasilla, José Luis Martins, Allan M. Matthews, Jaymie Mayer, Jean-Sébastien Messias, Yuri S. Metchev, Stan Mounzer, Dany Nari, Nicola Osborn, Ares Ouellet, Mathieu Parc, Léna Pasquini, Luca Peroux, Céline Piaulet-Ghorayeb, Caroline Pompei, Emanuela Poulin-Girard, Anne-Sophie Reshetov, Vladimir Saint-Antoine, Jonathan Sarajlic, Mirsad Schnell, Robin Segovia, Alex Seidel, Julia Silber, Armin Sinclair, Peter Sordet, Michael Sosnowska, Danuta Srivastava, Avidaan Stefanov, Atanas K. Teixeira, Márcio A. Thibault, Simon Vallée, Philippe Vandal, Thomas Vaulato, Valentina Wehbe, Bachar Weisserman, Drew Wevers, Ivan Wildi, François Yariv, Vincent Zins, Gérard |
| contents | The intense stellar irradiation of ultra-hot Jupiters results in some of the most extreme atmospheric environments in the planetary regime. On their daysides, temperatures can be sufficiently high for key atmospheric constituents to thermally dissociate into simpler molecular species and atoms. This dissociation drastically changes the atmospheric opacities and, in turn, critically alters the temperature structure, atmospheric dynamics, and day-night heat transport. To this date, however, simultaneous detections of the dissociating species and their thermally dissociation products in exoplanet atmospheres have remained rare. Here we present the simultaneous detections of H$_2$O and its thermally dissociation product OH on the dayside of the ultra-hot Jupiter WASP-121 b based on high-resolution emission spectroscopy with the recently commissioned Near InfraRed Planet Searcher (NIRPS). We retrieve a photospheric abundance ratio of log$_{10}$(OH/H$_2$O) $= -0.15\pm{0.20}$ indicating that there is about as much OH as H$_2$O at photospheric pressures, which confirms predictions from chemical equilibrium models. We compare the dissociation on WASP-121 b with other ultra-hot Jupiters and show that a trend in agreement with equilibrium models arises. We also discuss an apparent velocity shift of $4.79^{+0.93}_{-0.97} $km s$^{-1}$ in the H$_2$O signal, which is not reproduced by current global circulation models. Finally, in addition to H$_2$O and OH, the NIRPS data reveal evidence of Fe and Mg, from which we infer a Fe/Mg ratio consistent with the solar and host star ratios. Our results demonstrate that NIRPS can be an excellent instrument to obtain simultaneous measurements of refractory and volatile molecular species, paving the way for many future studies on the atmospheric composition, chemistry, and the formation history of close-in exoplanets. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2508_06626 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Quantifying thermal water dissociation in the dayside photosphere of WASP-121 b using NIRPS Bazinet, Luc Allart, Romain Benneke, Björn Pelletier, Stefan Wardenier, Joost P. Cook, Neil J. Forveille, Thierry Nielsen, Louise D. Moulla, Khaled Al Artigau, Étienne Baron, Frédérique Barros, Susana C. C. Bonfils, Xavier Bouchy, François Bryan, Marta Martins, Bruno L. Canto Cloutier, Ryan Cowan, Nicolas B. de Freitas, Daniel Brito De Medeiros, Jose Renan Delfosse, Xavier Doyon, René Dumusque, Xavier Ehrenreich, David Hernández, Jonay I. González Lafrenière, David Leão, Izan de Castro Lovis, Christophe Malo, Lison Melo, Claudio Mignon, Lucile Mordasini, Christoph Pepe, Francesco Rebolo, Rafael Rowe, Jason Santos, Nuno C. Ségransan, Damien Mascareño, Alejandro Suárez Udry, Stéphane Valencia, Diana Wade, Gregg Abreu, Manuel Aguiar, José L. A. Allain, Guillaume Arial, Tomy Auger, Hugues Blind, Nicolas Bohlender, David Boucher, Anne Bourrier, Vincent Bovay, Sébastien Broeg, Christopher Brousseau, Denis Cabral, Alexandre Cadieux, Charles Carmona, Andres Challita, Zalpha Chazelas, Bruno Coelho, João Cointepas, Marion Silva, Ana Rita Costa Coulombe, Louis-Philippe Cristo, Eduardo Darveau-Bernier, Antoine Dauplaise, Laurie Gomes, Roseane de Lima Fontinele, Dasaev O. Frensch, Yolanda G. C. Genest, Frédéric Genolet, Ludovic Témich, Félix Gracia Hernandez, Olivier Hoeijmakers, H. Jens Hubin, Norbert Jayawardhana, Ray Käufl, Hans-Ulrich Kerley, Dan Kolb, Johann Krishnamurthy, Vigneshwaran Kung, Benjamin Lamontagne, Pierrot Lim, Olivia Curto, Gaspare Lo Rasilla, José Luis Martins, Allan M. Matthews, Jaymie Mayer, Jean-Sébastien Messias, Yuri S. Metchev, Stan Mounzer, Dany Nari, Nicola Osborn, Ares Ouellet, Mathieu Parc, Léna Pasquini, Luca Peroux, Céline Piaulet-Ghorayeb, Caroline Pompei, Emanuela Poulin-Girard, Anne-Sophie Reshetov, Vladimir Saint-Antoine, Jonathan Sarajlic, Mirsad Schnell, Robin Segovia, Alex Seidel, Julia Silber, Armin Sinclair, Peter Sordet, Michael Sosnowska, Danuta Srivastava, Avidaan Stefanov, Atanas K. Teixeira, Márcio A. Thibault, Simon Vallée, Philippe Vandal, Thomas Vaulato, Valentina Wehbe, Bachar Weisserman, Drew Wevers, Ivan Wildi, François Yariv, Vincent Zins, Gérard Earth and Planetary Astrophysics The intense stellar irradiation of ultra-hot Jupiters results in some of the most extreme atmospheric environments in the planetary regime. On their daysides, temperatures can be sufficiently high for key atmospheric constituents to thermally dissociate into simpler molecular species and atoms. This dissociation drastically changes the atmospheric opacities and, in turn, critically alters the temperature structure, atmospheric dynamics, and day-night heat transport. To this date, however, simultaneous detections of the dissociating species and their thermally dissociation products in exoplanet atmospheres have remained rare. Here we present the simultaneous detections of H$_2$O and its thermally dissociation product OH on the dayside of the ultra-hot Jupiter WASP-121 b based on high-resolution emission spectroscopy with the recently commissioned Near InfraRed Planet Searcher (NIRPS). We retrieve a photospheric abundance ratio of log$_{10}$(OH/H$_2$O) $= -0.15\pm{0.20}$ indicating that there is about as much OH as H$_2$O at photospheric pressures, which confirms predictions from chemical equilibrium models. We compare the dissociation on WASP-121 b with other ultra-hot Jupiters and show that a trend in agreement with equilibrium models arises. We also discuss an apparent velocity shift of $4.79^{+0.93}_{-0.97} $km s$^{-1}$ in the H$_2$O signal, which is not reproduced by current global circulation models. Finally, in addition to H$_2$O and OH, the NIRPS data reveal evidence of Fe and Mg, from which we infer a Fe/Mg ratio consistent with the solar and host star ratios. Our results demonstrate that NIRPS can be an excellent instrument to obtain simultaneous measurements of refractory and volatile molecular species, paving the way for many future studies on the atmospheric composition, chemistry, and the formation history of close-in exoplanets. |
| title | Quantifying thermal water dissociation in the dayside photosphere of WASP-121 b using NIRPS |
| topic | Earth and Planetary Astrophysics |
| url | https://arxiv.org/abs/2508.06626 |