High Resolution Stellar Spectroscopy

高分辨率恒星光谱

• 批准号: 8914917
• 负责人: Christopher Sneden
• 金额: $ 9.6万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-12-01 至 1992-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8914917&HistoricalAwards=false
• 关键词: Resolution; Stellar; Spectroscopy

One of the fundamental questions concerning the Milky Way Galaxy is its elemental composition and how this composition came about. It is believed that the original gas from which our Galaxy formed, consisted of entirely hydrogen and helium. Most of the heavier elements were formed since then by nucleosynthesis in stellar interiors and during stellar explosions. The aim of the research proposed here is to improve our under- standing of the origin and distribution of the chemical elements in our Galaxy. To this end, the Principal Investigator (PI) will focus on four distinct, but related projects: 1. Use abundance distribution curves for the Galaxy's halo stars to deduce the nature of the first generation of massive stars in the Galaxy and their nucleosynethesized products; 2. study the mixing of light elements (e.g., lithium, carbon, nitrogen, oxygen) in the convective envelopes of giant stars in the Galaxy's halo and disk; 3. use nebular absorption and emission lines of neutral gas in planetary nebulae to learn about the nuclear history of the precursor stars; and 4. take very high signal-to-noise spectra of diffuse interstellar bands towards selected, very lightly reddened lines of sight in order to obtain clues as to the bands'origin.

关于银河系的一个基本问题是它的元素组成以及这种组成是如何产生的。据信，我们银河系形成的原始气体完全由氢和氦组成。从那时起，大多数较重的元素都是在恒星内部和恒星爆炸期间通过核合成形成的。提出这项研究的目的是为了提高我们对银河系中化学元素来源和分布的了解。为此，首席调查员(PI)将专注于四个不同但相关的项目：1.利用银河系晕星的丰度分布曲线来推断银河系第一代大质量恒星的性质及其核对称产物；2.研究银河系晕盘中巨星对流包层中轻元素(如锂、碳、氮、氧)的混合；3.利用行星状星云中中性气体的星云吸收和发射线，了解前驱恒星的核历史；以及4.将漫射星际波段的极高信噪比光谱朝向选定的、非常淡红的视线，以便获得有关波段起源的线索。