Collaborative Research: Laboratory and Observational Investigations of Aluminum Oxide Analogs of Stardust

我们和我们周围的世界都是由星尘构成的。这个项目的目标是更多地了解星尘的性质。一些垂死的恒星会产生由铝和氧组成的尘埃，研究人员将通过天文观测和实验室工作来研究这些尘埃。在实验室里，研究小组将制造新的氧化铝粉尘类型，以了解它们如何与光相互作用。研究人员的实验室测量结果将为了解太空中尘埃的形成提供指导。天文观测追踪了物质如何在分子云中凝结形成恒星、行星，并最终形成生命。天文学是一门入门科学，是最早让孩子们兴奋的科学之一。作为该项目的一部分，研究人员还将在K-12课程中推广科学，这将使圣安东尼奥这个多元化城市的许多孩子受益。圣安东尼奥大部分学区的学生都是拉美裔。该团队将针对代表性不足的群体的学生，通过经过良好测试的光谱演示提供前沿研究。他们将创建一个课堂演示，将光和颜色与科学课程联系起来，这将与德克萨斯州的科学标准（德克萨斯州基本知识和技能；TEKS）保持一致。该团队将(1)产生、表征和确定由铝和氧组成的星尘类似物的光学特性；(2)应用这些光学特性来理解低质量和中等质量演化恒星周围的尘埃形成。特别是，研究人员将把实验室测量的光谱特征与观测到的光谱（主要是红外光谱）进行比较。新的粉尘类似物将通过四种合成方法制备：烟雾产生，加热水合铝固体，激光烧蚀和热灯丝反应器。这些样品将通过电子显微镜和可见光到中红外光谱进行结构和化学表征，以确定其复杂的介电功能。许多天文观测已经完成，包括美国国家科学基金会支持的双子座望远镜对附近恒星的中红外光谱。他们还将利用这些数据来完善这些恒星周围尘埃形成的理论模型。该奖项反映了美国国家科学基金会的法定使命，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。

We, and the world around us, are made of stardust. The goal of this project is to learn more about the nature of that stardust. Some dying stars produce dust made of aluminum and oxygen, which the investigators will study through both astronomical observations and laboratory work. In the lab, the team will make new aluminum oxide dust types to understand how they interact with light. The investigators’ lab measurements will be a guide to understanding how dust forms in space. The astronomical observations trace how the material condenses in molecular clouds to form stars, planets, and, eventually, life. Astronomy is a gateway science, one of the first that excites children. As part of this project, the investigators will also promote science across the K-12 curriculum and will benefit many children in the diverse city of San Antonio. Most San Antonio school districts are majority Hispanic. The team will target students from under-represented groups, by providing cutting edge research via a well-tested spectroscopy demo. They will create a classroom demonstration that relates light and colors to the science curriculum, which will align with Texas' science standards (Texas Essential Knowledge and Skills; TEKS).The team will (1) produce, characterize, and determine optical properties of stardust analogs composed of aluminum and oxygen; and (2) apply these optical properties to understanding dust formation around low- and intermediate-mass evolved stars. In particular, the investigators will compare lab-measured spectral features to those seen in observational (mostly infrared) spectra. New dust analogs will be prepared using four synthesis methods: smoke production, heating of hydrated aluminous solid, laser ablation, and a hot filament reactor. These samples will be characterized structurally and chemically by electron microscopy, and spectroscopically in the visible to mid-infrared, in order to determine their complex dielectric functions. Many of the astronomical observations are already complete, including mid-infrared spectra of nearby stars from the NSF-supported Gemini Telescopes. They will also use the data to refine theoretical models for how dust forms around these stars.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.