Following the Chemical History of Stellar Ejecta through Molecular Observations and Laboratory Spectroscopy

该项目旨在揭示银河系中的物质是如何从恒星（产生大部分化学元素）转移到星际空间的。首席研究员和她的学生和合作者将检查最终将创建新太阳系的材料的化学成分。 这将有助于了解恒星喷射出的元素（包括生命必需的元素）的变化。该研究是高度跨学科的，涉及天文学、化学、行星科学和物理学相互关联的观测和实验室研究。这项研究几乎完全由研究生进行，这个实验室一直是未来科学家卓有成效的训练场。 PI 还参与物理科学跨学科课程的开发。演化恒星的星周包层和更先进的行星状星云 (PNe) 阶段的质量损失是星际介质 (ISM) 富含气体、尘埃和较重元素的主要途径。因此，星周壳层和随后的PNe的化学和物理特性对ISM中致密材料的整体生命周期具有重大影响。该项目的目标是（1）探测星周包膜和行星状星云的物理和化学特性，以确定其分子组成的范围，以及（2）通过射电/毫米波天文观测检查其形态结构。进一步的目标是使用实验室光谱学和额外的观察来识别这些物体中的新分子，特别是可能与灰尘颗粒（例如 TiOH 或 FeC2）有关的难熔物质。待研究的富含 O 的星周壳层包括超巨星英仙座 S 和渐近巨星分支 (AGB) 恒星 TX Cam 和 R Cas，将使用亚利桑那射电天文台 (ARO) 亚毫米望远镜 (SMT) 的高灵敏度 ALMA 型接收器和新型 ARO 12 米 ALMA 原型天线进行研究。 ARO 设施将寻找其他分子，目的是检验扩散云中充满了来自 PNe 的残余分子材料的革命性概念。

This project seeks to unravel how matter in our Galaxy is transferred from stars, which create the majority of the chemical elements, to interstellar space. The PI and her students and collaborators will examine the chemical composition of material that eventually will create new solar systems. This will provide insight into what becomes of the elements ejected from stars, including elements that are essential for life. The research is highly interdisciplinary, involving both observational and laboratory studies that interrelate astronomy, chemistry, planetary science, and physics. This research will be almost entirely conducted by graduate students, and this lab has been a fruitful training ground for future scientists. The PI is also involved in the development of interdisciplinary courses in the physical sciences. Mass loss from circumstellar envelopes of evolved stars and the more advanced, planetary nebulae (PNe) stage, is a major avenue by which the interstellar medium (ISM) is enriched in gas, dust, and the heavier elements. The chemical and physical characteristics of circumstellar shells and subsequent PNe thus have major impact on the overall life cycle of dense material in the ISM. The goals of this project are (1) to probe the physical and chemical properties of circumstellar envelopes and planetary nebulae to determine the extent of their molecular composition, and (2) to examine their morphological structures through radio/millimeter-wave astronomical observations. A further aim is to identify new molecules in these objects, in particular refractory species possibly linked to dust grains such as TiOH or FeC2, using laboratory spectroscopy followed by additional observations. The O-rich circumstellar shells to be studied include those of the supergiant S Persei and the Asymptotic Giant Branch (AGB) stars TX Cam and R Cas, which will be investigated using the highly sensitive ALMA-type receivers at the Sub-millimeter Telescope (SMT) of the Arizona Radio Observatory (ARO), and the new ARO 12 meter ALMA-prototype antenna. Other molecules will be sought with the ARO facilities, with the purpose of examining the revolutionary concept that diffuse clouds are being populated with remnant molecular material from PNe.