Collaborative Research: Revealing Exoplanet Atmospheres Using High-Resolution Spectroscopy

由芝加哥大学和亚利桑那州立大学领导的一个研究小组将开展一项观测计划，以帮助回答有关绕遥远恒星运行的近距离巨行星大气层的四个科学问题：化学丰度如何追踪行星起源？ 大气温度如何取决于外部辐射、重力和成分？行星的动力场和磁场是如何控制风速的？在化学转变过程中，大气的性质是什么？该小组将通过讲习班培训科学界使用新技术探测行星大气层。讲习班将侧重于早期职业研究人员，并将通过为代表性不足的群体的年轻科学家提供资金支持来扩大参与。使用互相关技术的地面高分辨率光谱学是探测系外行星大气的一种强大但复杂的方法。该项目小组开发了一种互相关光谱大气反演方法，可以提取化学成分的详细限制。该团队将把这项技术应用于最先进的高分辨率数据集，以测量碳氧丰度比、大气金属丰度、碳同位素丰度、难熔物种丰度以及大气温度如何随压力变化。 该团队将使用三台最灵敏的高分辨率摄谱仪进行调查：Gemini South上的IGRINS，Gemini North上的MAROON-X和VLT上的ESTERO。这些仪器涵盖了光学到近红外的范围，可以获得来自主要难熔元素（Fe、Ti、V）和挥发性元素（C、N、O）及其各种原子和分子物种的同位素（C、Ti）的光谱线。这些调查将利用透射和相位分辨热发射测量，目标是30多个具有广泛物理参数的行星。研讨会与会者将通过如何准备观测和完整的端到端的减少和高分辨率数据的分析。研讨会的讲座将被记录并发布在网上，一套数据分析和大气检索软件将公开提供。该奖项反映了NSF的法定使命，并已被认为是值得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的支持。

A team led by the University of Chicago and Arizona State University will carry out an observational program to help answer four science questions regarding the atmospheres of close-in giant planets orbiting distant stars: How do chemical abundances trace planet origins? How does atmosphere temperature depend on external radiation, gravity, and composition? How do the dynamic and magnetic fields of planets govern wind speeds? And what are atmosphere properties across chemical transitions? The team will train the science community in the use of new techniques for probing planet atmospheres with workshops. Workshops will focus upon early career researchers and will broaden participation by providing monetary support for junior scientists from underrepresented groups. Ground-based, high-resolution spectroscopy using the cross-correlation technique is a powerful, but complex method for probing exoplanet atmospheres. The project team have developed an atmospheric retrieval approach for cross-correlation spectroscopy which enables the extraction of detailed constraints on chemical compositions. The team will apply this technique to state-of-the-art high-resolution datasets to measure carbon-to-oxygen abundance ratios, atmospheric metallicity, carbon isotopic abundances, refractory species abundances, and how atmospheric temperature varies with pressure. The team will be carrying out a survey using three of the most sensitive high-resolution spectrographs: IGRINS on Gemini South, MAROON-X on Gemini North, and ESPRESSO on the VLT. These instruments span the optical to the near-infrared, yielding access to spectroscopic lines from major refractory (Fe, Ti, V) and volatile (C, N, O) elements and their isotopologues (C, Ti) in a variety of atomic and molecular species. The surveys will utilize both transmission and phase-resolved thermal emission measurements, targeting more than 30 planets with a broad range of physical parameters. Workshop attendees will be walked through how to prepare observations and the full end-to-end reduction and analysis of high-resolution data. The workshop lectures will be recorded and posted online and a suite of data analysis and atmospheric retrieval software will be made publicly available.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.