利用 NIRPS 量化 WASP-121 b 日面 photosphere 中热水的解离
地球与行星天体物理
2025-10-01 v1
摘要
超热行星的强烈星际辐射导致其大气中存在最极端的环境。在其日面，温度可足以高于关键大气成分的热解沉降为更简单的分子物种和原子。这一解离显著改变大气的气体色散特性，从而关键性地改变温度结构、大气动力学和 日-夜热传导。迄今为止，同时检测解离物种及其热解沉降产物的案例仍属罕见。本文基于 NIRPS 高分辨率发射光谱，报告了对 WASP-121 b 日面 HO 及其热解沉降产物 OH 的同时检测结果。我们检索到 photospheric 丰度比 log(OH/HO) ，表明在 photospheric 气压下 OH 与 HO 浓度约为相同，这确认了化学平衡模型的预测。我们将 WASP-121 b 上的解离情况与其他超热行星进行比较，发现与平衡模型一致的趋势。我们还讨论了 HO 信号中 apparent velocity shift km s 的现象，这一现象尚未被当前的全局流体动力学模型所再现。最后，除了 HO 和 OH，NIRPS 数据还揭示了 Fe 和 Mg 的证据，据此我们推断出 Fe/Mg 比例与太阳值和宿主星值相符。我们的结果表明，NIRPS 能够作为获取 refractory 和 volatile 分子同时测量的优异仪器，为未来大量研究铺路，涵盖 close-in 小行星的大气组成、化学以及形成历史。
引用
@article{arxiv.2508.06626,
title = {Quantifying thermal water dissociation in the dayside photosphere of WASP-121 b using NIRPS},
author = {Luc Bazinet and Romain Allart and Björn Benneke and Stefan Pelletier and Joost P. Wardenier and Neil J. Cook and Thierry Forveille and Louise D. Nielsen and Khaled Al Moulla and Étienne Artigau and Frédérique Baron and Susana C. C. Barros and Xavier Bonfils and François Bouchy and Marta Bryan and Bruno L. Canto Martins and Ryan Cloutier and Nicolas B. Cowan and Daniel Brito de Freitas and Jose Renan De Medeiros and Xavier Delfosse and René Doyon and Xavier Dumusque and David Ehrenreich and Jonay I. González Hernández and David Lafrenière and Izan de Castro Leão and Christophe Lovis and Lison Malo and Claudio Melo and Lucile Mignon and Christoph Mordasini and Francesco Pepe and Rafael Rebolo and Jason Rowe and Nuno C. Santos and Damien Ségransan and Alejandro Suárez Mascareño and Stéphane Udry and Diana Valencia and Gregg Wade and Manuel Abreu and José L. A. Aguiar and Guillaume Allain and Tomy Arial and Hugues Auger and Nicolas Blind and David Bohlender and Anne Boucher and Vincent Bourrier and Sébastien Bovay and Christopher Broeg and Denis Brousseau and Alexandre Cabral and Charles Cadieux and Andres Carmona and Zalpha Challita and Bruno Chazelas and João Coelho and Marion Cointepas and Ana Rita Costa Silva and Louis-Philippe Coulombe and Eduardo Cristo and Antoine Darveau-Bernier and Laurie Dauplaise and Roseane de Lima Gomes and Dasaev O. Fontinele and Yolanda G. C. Frensch and Frédéric Genest and Ludovic Genolet and Félix Gracia Témich and Olivier Hernandez and H. Jens Hoeijmakers and Norbert Hubin and Ray Jayawardhana and Hans-Ulrich Käufl and Dan Kerley and Johann Kolb and Vigneshwaran Krishnamurthy and Benjamin Kung and Pierrot Lamontagne and Olivia Lim and Gaspare Lo Curto and José Luis Rasilla and Allan M. Martins and Jaymie Matthews and Jean-Sébastien Mayer and Yuri S. Messias and Stan Metchev and Dany Mounzer and Nicola Nari and Ares Osborn and Mathieu Ouellet and Léna Parc and Luca Pasquini and Céline Peroux and Caroline Piaulet-Ghorayeb and Emanuela Pompei and Anne-Sophie Poulin-Girard and Vladimir Reshetov and Jonathan Saint-Antoine and Mirsad Sarajlic and Robin Schnell and Alex Segovia and Julia Seidel and Armin Silber and Peter Sinclair and Michael Sordet and Danuta Sosnowska and Avidaan Srivastava and Atanas K. Stefanov and Márcio A. Teixeira and Simon Thibault and Philippe Vallée and Thomas Vandal and Valentina Vaulato and Bachar Wehbe and Drew Weisserman and Ivan Wevers and François Wildi and Vincent Yariv and Gérard Zins},
journal= {arXiv preprint arXiv:2508.06626},
year = {2025}
}
备注
Accepted in A&A