Open cluster s- and r-process abundances and the evolution of the Milky Way disk

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。Heather Jacobson被授予美国国家科学基金会天文学和天体物理学博士后奖学金，在密歇根州立大学开展一个研究和教育项目。开放星团的年龄和距离可以可靠地确定，长期以来一直被用来探测银河系盘的化学演化。到目前为止，疏散星团化学丰度的研究主要集中在铁、轻元素和α元素上，而从内盘到外盘以及外盘本身转变的确切性质仍然不清楚。雅各布森博士将通过高分辨率光谱学对银河系盘内疏散星团的大量样本进行详细的s-和r-过程元素丰度测定，重点是过渡区和外盘的星团。S和r过程元素，如钡和铕，是在低质量演化的渐近巨星分支恒星或II型超新星中，通过中子捕获在铁峰核上形成的。这些元素的丰度分布，以及之前的研究，将为银河系在盘上不同位置的化学富集历史提供更多线索，以及外盘是否比内盘有一个不同的进化历史。雅各布森还将根据“每日天文图片”网站和其他面向公众的材料，为非科学专业的学生设计一门新的天文学入门课程。本课程的一个重要组成部分将是阅读和讨论课程主题如何通过新闻媒体呈现给公众。该课程的目标不仅是提高学生的天文学知识，而且要使他们具备科学素养，以便他们能够阅读和识别科学文章的正确、不完整或误导性。最终目标将是为未来的领导人和决策者提供他们需要的科学背景和工具，以便就科学教育和政策做出明智的决策。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Dr. Heather Jacobson is awarded an NSF Astronomy and Astrophysics Postdoctoral Fellowship to carry out a program of research and education at Michigan State University. Open star clusters, whose ages and distances can be reliably determined, have long been used to probe the chemical evolution of the Milky Way disk. Until now, open cluster chemical abundance studies have focused on iron and the light and alpha-elements, and the exact nature of the transition from the inner disk to the outer disk and of the outer disk itself is still unclear. Dr. Jacobson will determine detailed abundances of s- and r-process elements via high-resolution spectroscopy for a large sample of open clusters in the Milky Way disk, with emphasis on clusters in the transition region and in the outer disk. S- and r-process elements such as barium and europium are formed via neutron-capture on to iron-peak nuclei inside low-mass evolved asymptotic-giant-branch stars or in Type II supernovae. The abundance distributions of these elements, along with those previously studied, will provide more clues to the chemical enrichment history of the Galaxy at different locations in the disk, and whether or not the outer disk has a distinct evolutionary history than the inner disk.Dr. Jacobson will also design a new introductory astronomy class for non-science majors based upon the "Astronomy Picture of the Day" website and other material geared towards the general public. A significant component to the course will be to read and discuss how course topics are represented by the news media to the general public. The goals of the course are not only to improve students' knowledge of astronomy, but to make them scientifically literate so they can read and identify where science articles may be correct, incomplete or misleading. The ultimate goal will be to give future leaders and policy-makers the scientific background and tools they need to make informed decisions about science education and policy.