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

研究人员将观察一类特殊的老恒星，称为天琴座RR恒星，位于银河系中心。研究这些恒星让我们得以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样本，以重建它们在太空中的运动。然后，重建的运动将使研究人员能够区分哪些天琴座RR恒星是围绕银河系中心的光晕、圆盘或“球状凸起”的一部分。这些测量将有助于更好地了解银河系形成的早期阶段。调查员将招收合格的学生，目标是科学、技术、工程和数学(STEM)学科的第一代学生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，并在会议上发表讲话。调查员将继续领导科普咖啡馆系列活动，组织明星聚会，并与当地男孩和女孩俱乐部合作，与当地社区接触。调查员将使用天琴座RR恒星作为测试探测器，研究内银河系的形成。使用这种古老而贫金属的恒星是很重要的，因为大多数被用来了解内银河系的恒星群体都是更年轻、更富金属的。凸起中最古老的恒星，如天琴座RR恒星，出现在我们银河系恒星形成和组装的最早阶段。这些观测将与互补的光学测量相结合，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5,000颗天琴座RR恒星的径向速度和[Fe/H]金属含量，并提供天琴座RR恒星朝向银河系内部的完整轨道分析。这项奖励反映了NSF的法定任务，并通过使用基金会的智力优势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.