利用 JWST NIRCam 对系外行星 WASP-39b 的早期释放科学观测
地球与行星天体物理
2023-03-15 v1 天体物理仪器与方法
太阳与恒星天体物理
摘要
测量系外行星大气中的金属丰度和碳氧（C/O）比是约束主导化学过程并（若在平衡态）揭示行星形成历史的基本步骤。透射光谱通过约束含氧和含碳物种的丰度提供了必要手段；然而，这需要宽波长覆盖、适中光谱分辨率和高精度，而这些此前无法由已有的观测台同时实现。随着 JWST 已开展科学观测，我们能够在先前未涉足的波长和光谱分辨率下观测系外行星。在此，我们报告利用 JWST 近红外相机（NIRCam）对凌星系外行星 WASP-39b 的时间序列观测。长波长光谱和短波长测光光曲线覆盖 2.0–4.0 μm，表现出极小的系统误差，并揭示了该行星光谱中明确的分子吸收特征。具体而言，我们探测到大气中的气态 H₂O，并对 CH₄ 的丰度给出了上限。原本在 2.8 μm 处显著的 CO₂ 特征很大程度上被 H₂O 掩盖。最佳拟合化学平衡模型倾向于 1–100× 太阳的大气金属丰度（即相对于太阳重元素 enrichments 高于氦）和亚恒星的碳氧（C/O）比。推断的高金属丰度和低 C/O 比可能表明行星形成过程中显著吸积了固体物质，或上层大气中的非平衡过程。
引用
@article{arxiv.2211.10489,
title = {Early Release Science of the exoplanet WASP-39b with JWST NIRCam},
author = {Eva-Maria Ahrer and Kevin B. Stevenson and Megan Mansfield and Sarah E. Moran and Jonathan Brande and Giuseppe Morello and Catriona A. Murray and Nikolay K. Nikolov and Dominique J. M. Petit dit de la Roche and Everett Schlawin and Peter J. Wheatley and Sebastian Zieba and Natasha E. Batalha and Mario Damiano and Jayesh M Goyal and Monika Lendl and Joshua D. Lothringer and Sagnick Mukherjee and Kazumasa Ohno and Natalie M. Batalha and Matthew P. Battley and Jacob L. Bean and Thomas G. Beatty and Björn Benneke and Zachory K. Berta-Thompson and Aarynn L. Carter and Patricio E. Cubillos and Tansu Daylan and Néstor Espinoza and Peter Gao and Neale P. Gibson and Samuel Gill and Joseph Harrington and Renyu Hu and Laura Kreidberg and Nikole K. Lewis and Michael R. Line and Mercedes López-Morales and Vivien Parmentier and Diana K. Powell and David K. Sing and Shang-Min Tsai and Hannah R Wakeford and Luis Welbanks and Munazza K. Alam and Lili Alderson and Natalie H. Allen and David R. Anderson and Joanna K. Barstow and Daniel Bayliss and Taylor J. Bell and Jasmina Blecic and Edward M. Bryant and Matthew R. Burleigh and Ludmila Carone and S. L. Casewell and Quentin Changeat and Katy L. Chubb and Ian J. M. Crossfield and Nicolas Crouzet and Leen Decin and Jean-Michel Désert and Adina D. Feinstein and Laura Flagg and Jonathan J. Fortney and John E. Gizis and Kevin Heng and Nicolas Iro and Eliza M. -R. Kempton and Sarah Kendrew and James Kirk and Heather A. Knutson and Thaddeus D. Komacek and Pierre-Olivier Lagage and Jérémy Leconte and Jacob Lustig-Yaeger and Ryan J. MacDonald and Luigi Mancini and E. M. May and N. J. Mayne and Yamila Miguel and Thomas Mikal-Evans and Karan Molaverdikhani and Enric Palle and Caroline Piaulet and Benjamin V. Rackham and Seth Redfield and Laura K. Rogers and Pierre-Alexis Roy and Zafar Rustamkulov and Evgenya L. Shkolnik and Kristin S. Sotzen and Jake Taylor and P. Tremblin and Gregory S. Tucker and Jake D. Turner and Miguel de Val-Borro and Olivia Venot and Xi Zhang},
journal= {arXiv preprint arXiv:2211.10489},
year = {2023}
}
备注
35 pages, 13 figures, 3 tables, Nature, accepted