The Composition of Stars and Star Clusters in the Galaxy

银河系中恒星和星团的组成

• 批准号: 9016778
• 负责人: Ann Boesgaard
• 金额: $ 16.18万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-03-01 至 1995-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9016778&HistoricalAwards=false
• 关键词: Composition; Stars; Star; Clusters; Galaxy

One of the most basic questions astronomers are asked by the layman is "where did the atoms composing the Earth and our bodies" come from?" Indeed during the last generation astronomers have put a great deal of work into answering this question by mapping the enrichment of interstellar gas by heavy element atoms from stellar explosions that occur after these atoms are formed from hydrogen by complex nucleosynthetic reactions in the deep interiors of highly evolved stars. Although earlier work concentrated on determining the chemical abundance of the iron group elements, recent investigations have shown that the iron-group abundance enhancements did not start until comparatively late in the history of the Galaxy. Better indicators of enrichment during the early era (including the first hour after the Big Bang) are provided by the elements oxygen, carbon, and beryllium. The oldest stars betray this history best, but they are faint and difficult to observe. Moreover, the absorption line leading to abundance determinations of beryllium is located in the ultraviolet part of the spectrum that is inaccessible to Earth-based astronomers except in high mountain, low-latitude observatories such as Mauna Kea in Hawaii. The Principal Investigator (PI) has been active in studying chemical evolution studies of old stars in the Galaxy for years and will extend her investigation to the faint halo stars in the Galaxy with this three year award. Recent advances in detector technology should also permit the PI to obtain not only more accurate abundances but also to sample the chemical evolution in stars that were formed during the original collapse of the Galaxy from a proto-galactic cloud. The abundance results for beryllium may also permit a more constrained model of the Big Bang to be developed.

天文学家被外行人问到的最基本的问题之一 是“组成地球和我们身体的原子”从何而来 从哪里来的？“事实上，在上一代天文学家已经把一个 为了回答这个问题，我们做了大量的工作， 恒星重元素原子对星际气体的富集作用 氢原子形成后发生的爆炸 通过复杂的核合成反应， 高度进化的恒星 虽然早期的工作集中在 确定铁族元素的化学丰度， 最近的研究表明， 直到历史上相对较晚的时候， 银河系。 早期浓缩的更好指标 时代（包括大爆炸后的第一个小时）是由 氧碳铍元素 最古老的恒星 背叛这段历史最好，但他们是微弱的，很难 观察。 此外，导致丰度的吸收线 铍的测定位于紫外线部分， 地球上的天文学家无法到达的光谱， 在高山、低纬度天文台，如夏威夷莫纳克亚山， 夏威夷。 主要研究者（PI）一直积极参与 研究银河系中古老恒星的化学演化， 年，并将她的调查扩展到微弱的晕星， 银河系与这个三年奖。 探测器的最新进展 技术还应允许PI不仅获得更多 准确的丰度，而且还可以采样化学演变， 在银河系最初的坍缩过程中形成的恒星 来自原银河系云 铍的丰度结果 也可能允许一个更受约束的大爆炸模型， 开发