Lab Astro for Studies of the Synthesis of Fe-group Elements

用于研究 Fe 族元素合成的 Lab Astro

• 批准号: 1211055
• 负责人: James Lawler
• 金额: $ 29.22万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1211055&HistoricalAwards=false
• 关键词: Lab; Astro; Studies; Synthesis; Fe

This award will provide continuing support for the Wisconsin Atomic Transition Probability (WATP) program. The project includes the completion of very precise and accurate transition probability measurements of Titanium. These measurements will include the very important weak lines with low excitation potential in Ti II. Such lines sample the majority of the titanium in the photospheres of stars. Similar measurements will subsequently be extended to cobalt, nickel, and vanadium. Emission branching fractions will be measured using available spectra from a Fourier transform spectrometer and new data from a recently developed 3 m focal length vacuum echelle spectrograph. Radiative lifetime measurements will be performed on atom/ion beams using a WATP program time-resolved laser induced fluorescence experiment. Systematic uncertainties on these iron-group measurements will be 5% or less with high confidence. Collaborating astronomers will apply this lab data to determine highly reliable relative iron-group abundances in (old) metal-poor stars.The research effort will include the training of undergraduate and graduate students. The project is expected to aid in the interpretation of future large-scale spectroscopic surveys of metal-poor stars in the outskirts of the Milky Way.

该合同将为威斯康星原子跃迁概率（WATP）项目提供持续支持。该项目包括完成非常精确和准确的钛跃迁概率测量。这些测量将包括Ti II中具有低激发电位的非常重要的弱线。这样的谱线采样了恒星光球中的大部分钛元素。随后，类似的测量将扩展到钴、镍和钒。发射分支分数将使用傅立叶变换光谱仪的可用光谱和最近开发的3米焦距真空梯队光谱仪的新数据进行测量。辐射寿命测量将执行原子/离子束使用WATP程序时间分辨激光诱导荧光实验。这些铁基团测量的系统不确定度在高置信度下为5%或更小。合作的天文学家将利用这些实验室数据来确定（古老的）金属贫乏恒星中铁元素的相对丰度。研究工作将包括对本科生和研究生的培训。该项目预计将有助于解释未来对银河系外围金属贫乏恒星的大规模光谱调查。