A Search for Low-Frequency Recombination Lines in the Southern Galaxy

寻找南星系低频复合线

• 批准号: 9200831
• 负责人: William Erickson
• 金额: $ 2.47万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-04-15 至 1995-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9200831&HistoricalAwards=false
• 关键词: Search; Low; Frequency; Recombination; Lines

This award will support a survey of low frequency spectral lines from the southern portion of the plane of our Galaxy. The lines are produced by the recombination of ionized carbon atoms into very high quantum states with principal quantum numbers between 272 and 768; the corresponding frequencies of the lines are 325 MHz to 14.5 MHz. The atoms producing these lines are extremely large and fragile with diameters up to 50 microns. Such atoms can exist only under the benign conditions found in cool interstellar clouds, and they are extremely sensitive to their environment. For this reason they are excellent diagnostics of temperature, pressure, and ionization levels in cool interstellar clouds. All previous observations have been made with northern hemisphere telescopes. This survey will cover the southern portion of the galactic plane and the Magellanic Clouds using the Parkes telescope in Australia in order to discover more line emitting regions.

该奖项将支持低频谱线的调查 从我们银河系平面的南部。 的线 是由电离的碳原子重组成 主量子数在272和274之间的更高量子态 768;线路的相应频率为325 MHz至14.5 MHz MHz. 产生这些线的原子非常大， 易碎，直径可达50微米。 这样的原子只能存在于 在凉爽的星际云中发现的良性条件下， 它们对环境极为敏感。 为此 它们是对温度、压力和 冷星际云的电离水平。 所有先前 已经用北方的望远镜进行了观测。 这次巡天将覆盖银道面的南部 和麦哲伦星云的对比 以便发现更多的线发射区域。