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

我们和我们周围的世界，都是由星尘组成的。这个项目的目标是更多地了解这种星尘的性质。一些垂死的恒星产生由铝和氧气组成的尘埃，研究人员将通过天文观测和实验室工作对其进行研究。在实验室中，该团队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将指导我们了解尘埃是如何在太空中形成的。天文观测追踪了这种物质如何在分子云中凝聚形成恒星、行星，并最终形成生命。天文学是一门入门科学，是最能让孩子们兴奋的科学之一。作为该项目的一部分，研究人员还将在整个K-12课程中推广科学，并将使圣安东尼奥这个多元化城市的许多儿童受益。圣安东尼奥的大多数学区都是西班牙裔。该团队将瞄准来自代表性不足群体的学生，通过一个经过充分测试的光谱学演示提供尖端研究。他们将创建一个将光和颜色与科学课程联系起来的课堂演示，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。研究小组将(1)产生、表征和确定由铝和氧组成的星尘类似物的光学性质；以及(2)应用这些光学性质来了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(主要是红外)光谱中看到的光谱特征进行比较。将使用四种合成方法来制备新的粉尘类似物：烟雾产生、水合铝固体加热、激光烧蚀和热丝反应器。这些样品将通过电子显微镜进行结构和化学表征，并在可见光到中红外光谱中进行表征，以确定其复杂的介电功能。许多天文观测已经完成，包括由NSF支持的双子座望远镜拍摄的附近恒星的中红外光谱。他们还将利用这些数据来完善尘埃如何在这些恒星周围形成的理论模型。这一奖项反映了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。

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.