Molecular Gas in the Centers of Galaxies

星系中心的分子气体

• 批准号: 9417968
• 负责人: J. Turner
• 金额: $ 24.74万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-01-15 至 2000-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9417968&HistoricalAwards=false
• 关键词: Molecular; Gas; Centers; Galaxies

ABSTRACT AST 94-17968 Turner, Jean Interstellar gas provides the fuel for star formation, luminous star bursts, and active galactic nuclei, phenomena which are most apparent in galactic nuclei. Radio and millimeter wave emission line observations permit study of the distribution and dynamics of gas in galaxies. For this project, millimeter interferometric observations will be made of carbon monoxide (CO) in nearby galaxies. High resolution measurements near a galactic nucleus allow mapping the molecular gas at close to the resolution of individual molecular clouds ( 20 parsecs). From such mapped images, one can determine the mass of molecular gas, the orbits of molecular clouds, and from the orbits, how mass is distributed in the central regions. Previous work has shown, for example, that for many galaxies mapped in CO, more than half of the total mass within the inner few hundred parsecs is molecular gas. With multi-transition CO observations, one can infer cloud properties such as temperature and density and study how these properties vary with location in the galaxy. Finally, mapping the large-scale structure of the galactic disk in both CO and in the atomic hydrogen 21 cm line permits examination of the linkage between nuclear gas and disk gas.

摘要 AST 94-17968 Turner, Jean 星际气体为恒星形成、发光星爆发和活动星系核提供燃料，这些现象在星系核中最为明显。无线电和毫米波发射线观测可以研究星系中气体的分布和动力学。 对于该项目，将对附近星系中的一氧化碳（CO）进行毫米干涉观测。星系核附近的高分辨率测量允许以接近单个分子云的分辨率（20 秒差距）绘制分子气体图。 从这些映射图像中，人们可以确定分子气体的质量、分子云的轨道，并根据轨道确定质量在中心区域的分布情况。例如，之前的工作表明，对于绘制在二氧化碳中的许多星系来说，内部几百秒差距内总质量的一半以上是分子气体。 通过多跃迁二氧化碳观测，人们可以推断温度和密度等云特性，并研究这些特性如何随星系中位置的变化而变化。最后，在 CO 和原子氢 21 厘米线中绘制银河盘的大尺度结构，可以检查核气体和盘气体之间的联系。