Chemical Abundances in the Intergalactic Medium: Evolution and Constraints on Feedback From Galaxy Formation

星系际介质中的化学丰度：星系形成反馈的演化和限制

• 批准号: 0908920
• 负责人: Robert Simcoe
• 金额: $ 37.5万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0908920&HistoricalAwards=false
• 关键词: Chemical; Abundances; Intergalactic; Medium; Evolution

Dr. Simcoe will use instruments on the Magellan telescopes in Chile to study the buildup of carbon and oxygen in the intergalactic gas early in cosmic history, before and during the period when the galaxies made most of their stars. These 'heavy' chemical elements are produced inside stars, and released into interstellar gas as the stars die. In young galaxies, both their active nuclei and violent starbirth can eject heavy-element-rich gas into intergalactic space. Thus the amount of carbon and oxygen in the intergalactic gas traces the formation of the galaxies. The strongest spectral lines of highly-ionized carbon and oxygen are in the ultraviolet. But in the spectra of distant quasars, cosmic expansion means that we observe these lines at wavelengths longer by the redshift factor 1+z, so they are seen at visible or even infrared wavelengths. Dr. Simcoe will take high-quality optical spectra to derive carbon and oxygen abundances for gas that lies between us and luminous quasars in the redshift range 2.5z4.5. Studies of the 14 known quasars with z5.8 that are accessible from the Southern-hemisphere Magellan telescopes will be a first science project for the FIRE infrared spectrograph, which Dr. Simcoe has built under an earlier NSF grant. FIRE should be ready to go to the telescope in late 2009. A graduate student will be trained by working on this project. Dr. Simcoe will continue to train undergraduate students through MIT's UROP program; he has already mentored five students through this program, four of whom were members of groups under-represented in the physical sciences. During this early science project with FIRE, Dr. Simcoe and his team will optimize the reduction and analysis tools, and make them available to the Magellan user community.

Simcoe博士将在智利的麦哲伦望远镜上使用仪器来研究宇宙历史早期，在星系制造大部分恒星之前和期间，在宇宙历史早期和宇宙历史上的碳和氧气中积聚。 这些“重”化学元素是在星体内部产生的，并在星星死亡时释放到星际气体中。 在年轻的星系中，它们的活性核和暴力星源都可以将富含重元素的气体喷射到白术空间中。 因此，在半层次气体中的碳和氧气痕迹追溯了星系的形成。 高度离子碳和氧气的最强光谱线在紫外线中。 但是在远处的类星体的光谱中，宇宙膨胀意味着我们在红移因子1+z处观察到这些线长度，因此在可见的甚至红外波长处看到它们。 Simcoe博士将采用高质量的光谱，以得出我们与红移范围内的碳氧气丰度2.5z4.5。 可以从南部山脉麦哲伦望远镜访问的14个已知类星体的研究将是消防红外光谱仪的第一个科学项目，Simcoe博士根据早期的NSF拨款建造了该项目。 火灾应该在2009年底准备去望远镜。将通过从事该项目来培训一名研究生。 Simcoe博士将继续通过MIT的Urop计划培训本科生；他已经通过这项计划指导了五名学生，其中四名是体育科学中人数不足的团体的成员。 在此早期的科学项目中，Simcoe博士和他的团队将优化减少和分析工具，并将其提供给Magellan用户社区。