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。原行星盘冰促进尘埃颗粒和微行星的生长。了解驱动冰化学的物理和化学过程是至关重要的，因为人们认为，冰冷的小行星向早期地球提供了生物关键挥发物。即将到来的地面和空间观测站将探测行星盘中的冰，但解释冰观测结果将是具有挑战性的。该研究小组将对冰的特征进行建模，这将揭示在各种条件下冰在磁盘中的可检测性。这些模型对于解释即将到来的对盘的化学丰度、物理状态、进化轨迹和宜居行星形成倾向的观察将是无价的。该小组将对三个不同的目标年龄组进行外展：中学生、大学生和公众。他们将与弗吉尼亚大学的“女孩探索宇宙”暑期项目合作开发新项目，该项目由主要研究者担任联合主任。该小组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在内的当地外展组织合作，让公众参与宜居行星形成和冰所发挥的重要作用。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变，然后是辐射传输模型，以模拟冰光谱特征的观测。该工作将为理解盘状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型; 2）将冰特征极化模拟加入辐射传输模型; 3）对盘状冰的各个区域进行敏感性分析，以更好地解释哪些冰库是可观测的; 4）探索恒星、尘埃和盘属性（包括径向子结构）的参数空间，以预测它们对盘冰的影响; 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，这项研究将探索可观测（和不可观测）的盘状冰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，并被认为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来支持。

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.