系外行星大气中二氧化碳的证认
地球与行星天体物理
2023-03-22 v1
摘要
二氧化碳（CO2）是一种在广泛行星大气中发现的关键化学物种。在系外行星语境下，CO2 是金属丰度（即比氦重的元素，亦称“金属度”）以及热气态巨行星原初大气形成过程的指示物。它也是在类地系外行星次生大气中最为有望探测的物种之一。此前用斯皮策空间望远镜对凌星行星的光度测量给出了 CO2 存在的迹象，但由于缺乏明确的光谱证认而未能给出确定性探测。本文中，我们呈现了作为早期释放科学计划（ERS）一部分、用 JWST 透射光谱观测在气态巨行星系外行星 WASP-39b 大气中 CO2 的探测。本研究使用的数据波长覆盖 3.0 至 5.5 {\mu}m，并在 4.3 {\mu}m 处显示出显著的 CO2 吸收特征（26{\sigma} 显著性）。整体光谱与假设辐射-对流-热化学平衡且具有中等云不透明度的单维、10 倍太阳金属度模型吻合良好。这些模型预言大气除 CO2 外还应含有水、一氧化碳和硫化氢，但甲烷很少。此外，我们还暂探得 4.0 {\mu}m 附近的一个小吸收特征，未被这些模型复现。
引用
@article{arxiv.2208.11692,
title = {Identification of carbon dioxide in an exoplanet atmosphere},
author = {The JWST Transiting Exoplanet Community Early Release Science Team and Eva-Maria Ahrer and Lili Alderson and Natalie M. Batalha and Natasha E. Batalha and Jacob L. Bean and Thomas G. Beatty and Taylor J. Bell and Björn Benneke and Zachory K. Berta-Thompson and Aarynn L. Carter and Ian J. M. Crossfield and Néstor Espinoza and Adina D. Feinstein and Jonathan J. Fortney and Neale P. Gibson and Jayesh M. Goyal and Eliza M. -R. Kempton and James Kirk and Laura Kreidberg and Mercedes López-Morales and Michael R. Line and Joshua D. Lothringer and Sarah E. Moran and Sagnick Mukherjee and Kazumasa Ohno and Vivien Parmentier and Caroline Piaulet and Zafar Rustamkulov and Everett Schlawin and David K. Sing and Kevin B. Stevenson and Hannah R. Wakeford and Natalie H. Allen and Stephan M. Birkmann and Jonathan Brande and Nicolas Crouzet and Patricio E. Cubillos and Mario Damiano and Jean-Michel Désert and Peter Gao and Joseph Harrington and Renyu Hu and Sarah Kendrew and Heather A. Knutson and Pierre-Olivier Lagage and Jérémy Leconte and Monika Lendl and Ryan J. MacDonald and E. M. May and Yamila Miguel and Karan Molaverdikhani and Julianne I. Moses and Catriona Anne Murray and Molly Nehring and Nikolay K. Nikolov and D. J. M. Petit dit de la Roche and Michael Radica and Pierre-Alexis Roy and Keivan G. Stassun and Jake Taylor and William C. Waalkes and Patcharapol Wachiraphan and Luis Welbanks and Peter J. Wheatley and Keshav Aggarwal and Munazza K. Alam and Agnibha Banerjee and Joanna K. Barstow and Jasmina Blecic and S. L. Casewell and Quentin Changeat and K. L. Chubb and Knicole D. Colón and Louis-Philippe Coulombe and Tansu Daylan and Miguel de Val-Borro and Leen Decin and Leonardo A. Dos Santos and Laura Flagg and Kevin France and Guangwei Fu and A. García Muñoz and John E. Gizis and Ana Glidden and David Grant and Kevin Heng and Thomas Henning and Yu-Cian Hong and Julie Inglis and Nicolas Iro and Tiffany Kataria and Thaddeus D. Komacek and Jessica E. Krick and Elspeth K. H. Lee and Nikole K. Lewis and Jorge Lillo-Box and Jacob Lustig-Yaeger and Luigi Mancini and Avi M. Mandell and Megan Mansfield and Mark S. Marley and Thomas Mikal-Evans and Giuseppe Morello and Matthew C. Nixon and Kevin Ortiz Ceballos and Anjali A. A. Piette and Diana Powell and Benjamin V. Rackham and Lakeisha Ramos-Rosado and Emily Rauscher and Seth Redfield and Laura K. Rogers and Michael T. Roman and Gael M. Roudier and Nicholas Scarsdale and Evgenya L. Shkolnik and John Southworth and Jessica J. Spake and Maria E Steinrueck and Xianyu Tan and Johanna K. Teske and Pascal Tremblin and Shang-Min Tsai and Gregory S. Tucker and Jake D. Turner and Jeff A. Valenti and Olivia Venot and Ingo P. Waldmann and Nicole L. Wallack and Xi Zhang and Sebastian Zieba},
journal= {arXiv preprint arXiv:2208.11692},
year = {2023}
}
备注
27 pages, 6 figures, Accepted for publication in Nature, data and models available at https://doi.10.5281/zenodo.6959427