Uncovering the Hidden Ice Reservoir During Planet Formation

水冰在行星盘和行星的形成中起着关键作用。原行星盘冰有利于尘埃颗粒和行星体的生长。了解推动冰化学的物理和化学过程是至关重要的，因为人们认为冰行星向早期地球输送了生物关键的挥发物。即将到来的地面和空间天文台将探测行星盘中的冰，但解释冰观测将是具有挑战性的。这个研究小组将对冰水库进行建模，这将揭示在不同条件下盘中冰特征的可探测性。这些模型对于解释即将观测到的盘的化学丰度、物理状态、演化轨迹和形成宜居行星的倾向将是非常有价值的。该团队将面向三个不同的目标年龄段：中学生、本科生和普通民众。他们将与弗吉尼亚大学合作开发新的项目，由首席调查员担任联合主任，该项目针对中学女生的暑期项目是“女孩探索宇宙”。该团队还将支持本科生的培训。他们还将与包括夏洛茨维尔天文学会在内的当地外联组织合作，就宜居行星的形成和冰发挥的重要作用这一主题与公众进行接触。该团队将创建详细的随时间变化的气体-颗粒化学模型，以模拟行星盘中冰的分布和演化，随后将创建辐射传输模型，以模拟对冰光谱特征的观测。这项工作将通过以下方式为理解盘冰提供必要的理论基础：1)将颗粒生长和物质输运过程纳入化学演化模拟；2)在辐射传输模拟中加入冰特征极化的模拟；3)对盘不同区域的冰进行敏感性分析，以更好地解释哪些冰库是可观测的；4)探索恒星、尘埃和盘性质(包括径向子结构)的参数空间，以预测它们对盘冰的影响；以及5)研究盘的外部环境(紫外线和宇宙射线场)对可观测冰的影响。因此，这项调查将探索可观察到的(和不可观测的)盘冰水库的多样性及其与行星形成过程和结果的多样性的联系。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Water ice plays a key role in the formation of planetary disks and planets. Protoplanetary disk ices facilitate the growth of dust grains and planetesimals. Understanding the physical and chemical processes that drive ice chemistry is essential, because it is believed that icy planetesimals delivered bio-critical volatiles to the early Earth. Upcoming ground- and space-based observatories will probe ice in planetary disks, but interpreting ice observations will be challenging. This research team will model ice reservoirso, which will shed light on the detectability of ice features in disks under various conditions. These models will be invaluable for interpreting upcoming observations of disks' chemical abundances, physical state, evolutionary trajectory, and propensity for habitable planet formation. The team will conduct outreach to three different targeted age groups: middle schoolers, undergraduates, and the general public. They will collaborate on developing new programs with the Universty of Virginia's “Girls Exploring the Universe” summer program for middle school girls where the principal investigator serves as co-director. The team will also support the training of undergraduates. In partnership with local outreach organizations including Charlottesville's Astronomy on Tap, they will also engage the public on the topic of habitable planet formation and the important role played by ices. The team will create detailed time-dependent gas-grain chemical models to simulate the distribution and evolution of ices in planetary disks, followed by radiative transfer models to simulate observations of ice spectral signatures. The proposed work will provide the necessary theoretical underpinning to understand disk ice by: 1) Incorporating grain growth and material transport processes into the chemical evolution modeling; 2) Adding simulations of ice feature polarization to the radiative transfer modeling; 3) Conducting a sensitivity analysis of ices in various regions of the disk to better interpret which ice reservoirs are observable; 4) Exploring a parameter space of stellar, dust, and disk properties (including radial substructure) to predict their effects on disk ices; and 5) Studying the effect of a disk’s external environment (UV and cosmic ray fields) on observable ices. Thus, this investigation will explore the diversity of observable (and unobservable) disk icy reservoirs and their connection to the diversity of planet formation processes and outcomes.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.