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

该项目旨在揭示我们银河系中的物质是如何从恒星转移到星际空间的，恒星创造了大部分化学元素。PI和她的学生和合作者将研究最终创造新太阳系的材料的化学成分。这将使我们深入了解从恒星喷射出来的元素，包括生命所必需的元素的去向。这项研究是高度跨学科的，包括观测和实验室研究，将天文学、化学、行星科学和物理学联系起来。这项研究将几乎完全由研究生进行，这个实验室是培养未来科学家的一个卓有成效的基地。PI还参与开发物理科学领域的跨学科课程。演化恒星的星周包层和更高级的行星状星云（PNe）阶段的质量损失，是星际介质（ISM）富含气体、尘埃和重元素的主要途径。因此，星周壳和随后的PNe的化学和物理特性对ISM中致密物质的整个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性质，以确定其分子组成的程度；(2)通过射电/毫米波天文观测来研究它们的形态结构。进一步的目标是在这些物体中识别新分子，特别是可能与尘埃颗粒（如TiOH或FeC2）有关的难熔物质，使用实验室光谱，然后进行额外的观察。将研究的富含o的星周壳包括超巨星英仙座S和渐近巨星分支（AGB）恒星TX Cam和R Cas，它们将使用亚利桑那射电天文台（ARO）的亚毫米望远镜（SMT）上的高灵敏度alma型接收器和新的ARO 12米alma原型天线进行研究。其他分子将通过ARO设备寻找，目的是检验扩散云是由PNe残余分子物质填充的革命性概念。

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.