CAREER: How does external photoevaporation shape planets?

观测结果显示，除了太阳之外，还有许多行星绕着其他恒星运行。行星形成于新生恒星周围的气体和尘埃盘中，但随着恒星的老化，盘会消失，限制了行星形成的机会。超新星可能会螺旋进入中心的星星，或者通过新生的星星的光子从里到外蒸发。然而，来自附近更明亮的星星的外部光蒸发可以更快地摧毁磁盘，减少制造行星的时间和材料。虽然这种现象已经在一些物体中观察到，但该项目将量化这种外部光蒸发是否是行星形成的主要参与者。莱斯大学的Megan Reiter博士和她的研究伙伴将利用一个大型的年轻星星集群数据集来测量圆盘本身、照射在圆盘上的星光以及从圆盘上流走的物质。与此同时，一项鼓励进入和坚持STEM领域的教育计划将分两部分实施：休斯顿K-12学校的主动学习教师培训和天文学课程，以及莱斯大学的观测实验室课程将增加基础技能;这些干预措施将优先帮助历史上代表性不足的群体。为了量化这种环境对行星形成的影响，Reiter博士使用欧洲南方天文台甚大望远镜上的积分场单元摄谱仪MUSE获得了超过100小时的望远镜时间。其目标是观察数千颗低质量恒星及其在高质量恒星形成区域中的盘，这些恒星的质量至少是太阳质量的1000倍，这是一个比现有研究大100倍的样本。这些数据清楚地将恒星的辐射从明亮多变的星云背景中分离出来。光谱诊断表明积极的外部光蒸发和量化的质量损失率。入射紫外线通量和外部磁盘光蒸发之间的比例关系将被导出，当理论家模拟行星的人口统计时，这是有用的。当30米级地面望远镜可用时，将对这项工作所开发的方法和支持的天文学专业人员提出很高的要求。教育干预将包括价值参与评估，这是一种新的方式来测试更新的教学法是否提高了莱斯及其他地区STEM课程的保留率。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

Observations have revealed a remarkable diversity of planets orbiting stars other than the Sun. Planets form in disks of gas and dust around newborn stars, but disks disappear as the stars age, limiting the opportunity for planets to form. Disks may spiral into the central star or evaporate from the inside-out via the newborn star’s photons. However, external photoevaporation from a nearby, much brighter star can destroy disks more quickly, reducing the time and materials to make planets. While this phenomenon has been observed in a few objects, this project will quantify whether such external photoevaporation is a major player in this story of planet formation. Leveraging a large dataset of young star clusters, Dr. Megan Reiter of Rice University and her research associates will measure the disks themselves, starlight impinging on them, and matter streaming away from them. In parallel, an educational program to encourage entrance and persistence in STEM fields will be implemented in two parts: an active-learning teacher training and astronomy-inspired curriculum for Houston K-12 schools, and foundational skills will be added to observational lab courses at Rice University; these interventions will preferentially help historically underrepresented groups.To quantify this environmental impact on planet formation, Dr. Reiter has secured more than 100 hours of telescope time using the integral field unit spectrograph MUSE on the European Southern Observatory's Very Large Telescope. The goal is to observe thousands of low-mass stars and their disks in high-mass star-forming regions of at least 1000 times the mass of the Sun – a sample 100 times larger than existing studies. These data cleanly separate stellar emission from the bright, variable nebular background. Spectral diagnostics indicate active external photoevaporation and quantify the mass-loss rate. A scaling relationship between incident UV flux and external disk photoevaporation will be derived, useful when theorists model the demographics of planets. The methods developed and astronomy professionals supported by this work will be in high demand when 30-meter class ground-based telescopes become available. The educational intervention will include value-engaged evaluation, a new way to test whether updated pedagogy improves retention in STEM courses at Rice and beyond.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.