The Photochemistry of Low-Mass Exoplanets Across the Mini-Neptune / Super-Earth Regime

迷你海王星/超级地球体系中低质量系外行星的光化学

• 批准号: 2009095
• 负责人: Eliza Kempton
• 金额: $ 30.77万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2009095&HistoricalAwards=false
• 关键词: Photochemistry; Low; Mass; Exoplanets; Across

The powerful new capabilities soon to be provided by the James Webb Space Telescope (JWST) and by ground based "Extremely Large Telescopes" will enable many new astronomical observations. One of the most exciting of these will be obtaining spectra of the atmospheres of individual exoplanets. This team will provide a theoretical framework within which to understand these sorts of measurements. They will develop models for the photochemistry and chemical kinetics of exoplanetary atmospheres. This will include the formation and development of hazes and other atmospheric constituents. The team will conduct a robust K-12 outreach program. Graduate and undergraduate student volunteers will speak at schools local to the University. This program will also support the work of a graduate student.This research will advance chemical kinetics and photochemistry modeling of low-mass exoplanets to fill in critical gaps in our predictive and interpretive phase space. The team will develop the opensource numerical chemical kinetics code PHOTOCHEM to be applicable to a wider array of exoplanet environments, including hydrogen-rich sub-Neptunes and the metal-rich secondary atmospheres of super-Earths, pushing well beyond the modeling parameter space enabled by solar system studies. They will investigate several key open scientific questions and will provide a modeling framework for exoplanet observers performing spectroscopic studies of transiting planet atmospheres. The specific studies that the team will undertake include: (1) calculating photochemical haze formation rates for a broad parameter space of low-mass exoplanet atmospheres to make testable predictions for which sub-classes of planets should be most affected by photochemical aerosols; (2) determining the necessary level of precision and wavelength coverage for UV observations of exoplanet host stars to be used as input to photochemical modeling studies; (3) directly modeling the outcomes of laboratory haze experiments to provide a foundational basis for comparing between the theory and measurement of haze formation; (4) producing observables (transmission and emission spectra) for each of the modeled planets, to motivate and interpret atmospheric characterization studies with JWST and ground-based telescopes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

詹姆斯·韦伯太空望远镜（JWST）和地基“超大望远镜”即将提供的强大新能力将使许多新的天文观测成为可能。其中最令人兴奋的将是获得单个系外行星大气的光谱。该团队将提供一个理论框架，以了解这些类型的测量。他们将开发太阳系外行星大气的光化学和化学动力学模型。这将包括烟雾和其他大气成分的形成和发展。该团队将开展一项强有力的K-12外展计划。研究生和本科生志愿者将在大学当地的学校演讲。这项研究将推进低质量系外行星的化学动力学和光化学建模，以填补我们预测和解释相空间的关键空白。该团队将开发开源数值化学动力学代码PHOTOCHEM，以适用于更广泛的系外行星环境，包括富含氢的次海王星和超级地球富含金属的次级大气，远远超出太阳系研究所能实现的建模参数空间。他们将调查几个关键的开放式科学问题，并将为系外行星观测者提供一个建模框架，对过境行星大气进行光谱研究。该团队将开展的具体研究包括：（1）计算低质量系外行星大气的广泛参数空间的光化学雾霾形成率，以做出可测试的预测，确定哪些子类行星应最受光化学气溶胶的影响;（二）确定对系外行星主星进行紫外线观测所需的精度和波长覆盖范围，以用作光化学建模的输入研究;（3）直接模拟实验室灰霾实验结果，为灰霾形成的理论与测量的比较提供基础依据;（4）产生可观测量（透射和发射光谱）对于每个建模的行星，推动和解释与JWST和地面的大气特性研究，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Exoplanet Volatile Carbon Content as a Natural Pathway for Haze Formation

• DOI: 10.3847/2041-8213/acd377
• 发表时间: 2023-05
• 期刊: The Astrophysical Journal Letters
• 作者: E. Bergin;E. Kempton;M. Hirschmann;S. Bastelberger;D. Teal;G. Blake;F. Ciesla;Jie Li

The High-energy Spectrum of the Nearby Planet-hosting Inactive Mid-M Dwarf LHS 3844

• DOI: 10.3847/1538-3881/abfa1c
• 发表时间: 2021-04
• 期刊: The Astronomical Journal
• 作者: Hannah Diamond-Lowe;A. Youngblood;D. Charbonneau;G. King;D. Teal;S. Bastelberger;L. Corrales

Effects of UV Stellar Spectral Uncertainty on the Chemistry of Terrestrial Atmospheres

紫外恒星光谱不确定性对陆地大气化学的影响

• DOI: 10.3847/1538-4357/ac4d99
• 发表时间: 2022
• 期刊: The Astrophysical Journal
• 作者: Teal, D. J.;Kempton, Eliza M. -R.;Bastelberger, Sandra;Youngblood, Allison;Arney, Giada
• 通讯作者: Arney, Giada

Photochemical Hazes Can Trace the C/O Ratio in Exoplanet Atmospheres

光化学雾霾可以追踪系外行星大气中的 C/O 比率

• DOI: 10.3847/2041-8213/acaf86
• 发表时间: 2023
• 期刊: The Astrophysical Journal Letters
• 作者: Corrales, Lía;Gavilan, Lisseth;Teal, D. J.;Kempton, Eliza M.-R.
• 通讯作者: Kempton, Eliza M.-R.