Cosmic Evolution through Stellar Spectroscopy

我的研究是通过光谱丰度分析来研究恒星系统的化学演化。这样做的一个主要目的是了解星系从最早的时代开始的演化和丰富，以及改善我们对元素起源的理解。这项提议描述了在我们自己的和附近的矮小星系中进行这项工作的几个相关途径。对特定目标(贫金属星、化学奇特恒星、矮小星系中潮汐半径以外的恒星)的详细光谱分析可以解决元素的起源和星际介质的均质性、恒星风和超新星反馈对星系演化的影响以及合并对低质量系统化学演化的影响等问题。这一领域在过去十年中产生了重大影响，但我们才刚刚开始有足够的数据来比较附近的矮星系，并收集更孤立的矮不规则星系的数据。银河系中心是另一个有趣的区域，在那里尚未发现大量贫金属星，但数值模拟表明，First Stars在大质量晕引力中心附近点燃时是无金属的大质量恒星。我们已经启动了一项计划，利用光度和光谱技术在银河系凸起中搜索贫金属星-其中一项技术将包括首次使用斯巴鲁-乌鸦多对象自适应光学原型。在接下来的十年里，大型光谱学调查将会增加，虽然许多项目正在计划中，例如斯巴鲁-PFS和NOAO-DESI，但一些高分辨率的研究目前正在执行中，例如SDSS III-远地点和ESO-GAIA调查。通过公开发布，这些数据集(以及来自Herschel和ALMA的其他数据集)可以用来解决从银河系考古学到碎片盘形成的一系列问题。我的研究建议包括几个项目，这些项目非常适合学生和PDF的HQP培训。

My research is centered on the chemical evolution of stellar systems via spectroscopic abundance analyses. A major aim of this is to understand the evolution and enrichment of galaxies from the earliest epochs, as well as improving our understanding of the origins of the elements. This proposal describes several related avenues of such work, in our own and in nearby dwarf galaxies. Detailed spectroscopy of specific targets (metal-poor stars, chemically peculiar stars, stars beyond the tidal radii in dwarf galaxies) can address questions of the origins of the elements and the homogeneity of the interstellar medium, as well as the effects of stellar winds and supernova feedback on galaxy evolution, and the impact of mergers on the chemical evolution of low mass systems. This field has had a significant impact in the past decade, and yet we are only beginning to have sufficient data to compare the nearby dwarf galaxies to one another, and to collect data for the more isolated dwarf irregular galaxies. The Galactic Centre is another interesting region where metal-poor stars have yet to be found in significant numbers, and yet numerical simulations suggest that First Stars ignite as metal-free, massive stars near the gravitational centres of massive halos. We have initiated a program to search for metal-poor stars in the Galactic Bulge using both photometry and spectroscopic techniques – one of these will include first light use of the Subaru-RAVEN multi-object adaptive optics prototype. The next decade will see an increase in large spectroscopic surveys, and while many are being planned, such as Subaru-PFS and NOAO-DESI, some high resolution studies are currently being executed, such as SDSS III-APOGEE and the ESO-GAIA survey. Through public releases, these datasets (and others such as from Herschel and ALMA) can be used to address questions ranging from Galactic Archaeology to the formation of debris disks. My research proposal includes several projects that are ideal for HQP training of students and PDFs.