RUI: The BRAVA-RR Survey: uncovering an ancient Spheroidal Bulge in the Milky Way

研究人员将观察到一种特殊的古老恒星，称为天琴座RR星，位于银河系的中心。研究这些恒星可以让我们一窥银河系是如何随时间变化的。研究人员将观察这些恒星的大量样本，以便重建它们在太空中的运动。重建的运动将使研究人员能够区分哪些RR天琴座恒星是光环、圆盘或围绕银河系中心的“球状凸起”的一部分。这些测量将使我们更好地了解银河系形成的早期阶段。研究者将招募合格的学生，目标是科学、技术、工程和数学（STEM）学科的第一代和其他代表性不足的学生。这些学生研究人员将从望远镜收集数据，分析数据，并在会议上发表演讲。调查员将继续领导流行的公共科学咖啡系列，组织明星派对，并与当地男孩和女孩俱乐部合作，参与当地社区。研究人员将使用RR天琴座恒星作为测试探测器来研究内星系的形成。利用这些古老而缺乏金属的恒星是很重要的，因为大多数用来了解银河系内部的恒星群都更年轻，金属更丰富。突出部分最古老的恒星，如天琴座RR星，出现在银河系恒星形成和聚集的最早阶段。这些观测将与互补的光学观测相结合，为研究凸起的结构、动力学和金属丰度提供基础。这项提议将提供大约5000颗天琴座RR恒星的径向速度和[Fe/H]金属丰度，并提供天琴座RR恒星向内星系的完整轨道分析。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The investigator will observe a special class of old stars, called RR Lyrae stars, located toward the center of the Galaxy. Studying these stars provides a glimpse to how the Milky Way changed with time. The investigator will observe a large sample of these stars in order to reconstruct their motion through space. The reconstructed motions will then allow the investigator to distinguish which RR Lyrae stars are part of the halo, the disk, or the “Spheroidal Bulge” surrounding the center of the Milky Way. These measurements will lead to a better understand the early stages of the Milky Way formation. The investigator will recruit qualified students, targeting first generation and other underrepresented students within the science, technology, engineering and math (STEM) disciplines. These student researchers will collect data from telescopes, analyze the data, and present at conferences. The investigator will continue to lead the popular public science café series, organize star parties and work with the local Boys and Girls club to engage the local community.The investigator will use RR Lyrae stars as test probes to study the formation of the inner Galaxy. Using such ancient and metal-poor stars is important, as most of the stellar populations that have been used to understand the inner Galaxy have been younger and more metal-rich. The oldest stars in the Bulge, like the RR Lyrae stars, were present in the earliest episodes of star formation and assembly of our Galaxy. These observations will be combined with complementary optical surveys to provide the foundation of studies on the structure, dynamics and metallicity of the bulge. This proposal will provide both radial velocities and [Fe/H] metallicities for approximately 5,000 RR Lyrae stars and provide a full orbital analysis of the RR Lyrae stars toward the inner galaxy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.