Connecting Dwarf Galaxies, Metal Poor Stars, and the Origins of the Elements

连接矮星系、贫金属恒星和元素的起源

• 批准号: RGPIN-2020-07090
• 负责人: Venn, Kim
• 金额: $ 4.44万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741588
• 关键词: Connecting; Dwarf; Galaxies; Metal; Poor

The surfaces of stars contain a fossil fingerprint of the chemical composition of their birth clouds, and metal-poor stars are particularly important as tracers of the formation and assembly history of the Galaxy. Moreover, metal-poor stars are important for understanding the origins of the elements given that few nucleosynthetic events would have contributed to their chemical compositions. In the upcoming decade of large high-resolution spectroscopic, photometric, and astrometric surveys, samples of metal-poor stars with interesting origins and dynamics will be discovered throughout the Milky Way. Higher precision analyses will reveal their detailed compositions, allowing us to break degeneracies in stellar and galaxy modeling, to explore their origins and better understand the formation of the elements. This research program builds on my expertise in stellar spectroscopy and my successful collaboration with the Pristine survey to find rare metal-poor stars, leading to two long term goals: (1) Finding and analyzing metal-poor stars throughout the Milky Way and dwarf galaxies - Studies of metal-poor stars in the Milky Way and nearby satellites have shown chemical abundance patterns that differ due to a range of (degenerate) galactic and stellar modeling assumptions. Larger statistical samples are required to break those degeneracies and map the metal-poor Milky Way. (2) Understanding the origins of heavy r-process elements - The origin of the elements remains one of the great unsolved problems in physics, although a major breakthrough came with the discovery of r-process nucleosynthesis in a neutron star merger, as an addition to a ubiquitous r-process site. A comparison of metal-poor stars that formed in a variety of environments is needed to constrain these nucleosynthetic pathways. This research program will use the Gemini Observatory GRACES and upcoming GHOST spectrographs for high resolution (R>50,000) spectra of metal-poor stars; GHOST is particularly necessary for spectra below 450 nm for r-process element spectral lines. This program will also use spectra of metal-poor stars (~3000 targets) from the upcoming WEAVE spectroscopic survey. Therefore, this is an exciting time for the discovery and analysis of a large number of metal poor stars, in a variety of galactic environments (Galactic bulge, plane, globular clusters, streams, and in dwarf galaxies). The impact of my research program will be a better understanding of the origin of the heavy elements and the assembly history of the metal-poor Galaxy, leading to improvements in galaxy and stellar modeling. This program provides training opportunities for HQP in observational and theoretical astrophysics, and unique opportunities to develop new data analysis methodologies (e.g., machine learning algorithms) and to be involved in instrumentation developments (e.g., science verification for GHOST), thereby preparing for future Canadian facilities (e.g., TMT, MSE, or equivalents).

恒星的表面包含其出生云化学成分的化石指纹，而金属贫困的恒星尤其重要，因为示踪了银河系的形成和组装历史。此外，鉴于很少有核合成事件会导致其化学成分，因此金属贫困的恒星对于理解元素的起源很重要。在接下来的十年中，大型高分辨率光谱，光度法和天体调查，将在整个银河系中发现具有有趣起源和动力学的金属贫困星的样品。更高的精度分析将揭示其详细的组成，从而使我们能够打破恒星和星系建模中的脱落，以探索它们的起源并更好地理解元素的形成。这项研究计划以我在恒星光谱法的专业知识以及与原始调查的成功合作为基础，以找到罕见的金属贫困的明星，导致了两个长期目标：（1）在整个银河系中查找和分析金属贫困的星星，并且在整个银河系中，矮人的矮人的研究 - 对乳制品和附近的卫星模型中的金属贫困星体的研究，这些型号的卫星模式不同）假设。需要较大的统计样本来破坏这些变性并绘制金属贫穷的银河系。 （2）理解重型R过程的起源 - 元素的起源仍然是物理学中最大的未解决问题之一，尽管在中子星合并中发现了R-Process核合成的重大突破，这是无处不在的R-Process网站的补充。需要比较在各种环境中形成的金属贫困星来限制这些核合成途径。该研究计划将使用Gemini天文台的纹理和即将到来的幽灵光谱仪，用于高分辨率（R> 50,000）金属势力恒星；对于R-Process元素光谱线的450 nm低于450 nm的光谱特别必要。该程序还将使用即将进行的编织光谱调查中的金属贫困恒星（约3000个目标）的光谱。因此，在各种银河环境（银河凸起，平面，球状簇，溪流和矮星系）中发现和分析大量金属可怜恒星的令人兴奋的时刻。我的研究计划的影响将更好地理解重型元素的起源以及金属贫穷的银河系的组装历史，从而改善了银河系和恒星建模。 该计划为HQP提供了观察和理论天体物理学的培训机会，以及开发新的数据分析方法（例如机器学习算法）的独特机会，并参与仪器的发展（例如，幽灵的科学验证），从而为未来的加拿大设施做准备（例如，TMT，TMT，MSE，MSE，MSE或ECORACENTENT）。