Collaborative Research: Exploring the Galaxy and its White Dwarfs with the HET Dark Energy Experiment

来自德克萨斯大学奥斯汀分校和贝勒大学的研究小组计划对Hobby-Eberly望远镜暗能量实验（HETDEX）的现有观测进行新的分析，以更好地了解银河系中星星形成的历史。 虽然HETDEX主要用于暗能量的研究，但研究人员已经将调查重新用于银河天文学，体现了“一个人的垃圾是另一个人的宝藏”这句话。 研究人员将共同努力，参与，授权和招募各级天文学代表性不足的群体。在本科阶段，调查人员将通过UT Austin的Tarus项目重点培训代表性不足的少数民族学生。在社区一级，两名调查员将继续参加定期外联活动，例如，通过公开讲座，并创建一个新的“HETDEX调查之星”外展之夜。调查人员将使用HETDEX内观察到的超过100，000颗恒星的光谱：（1）提供这些恒星的大气参数，（2）使用导出的大气参数来约束恒星晕的组装，以及（3）对白色矮星进行深度调查，星星生命周期的最终产物，来限制形成的时间尺度。 HETDEX调查的无偏见和深度（15 G星等22）的性质使其与其他光谱调查相比，在拼凑银河系的组装方面非常强大。对数据的初步研究表明，径向速度可以测量，光谱可以用来寻找贫金属恒星。研究人员将通过以下方式大大扩展这项试点研究：（1）利用麦克唐纳天文台高分辨率仪器的快速访问，确认HETDEX中确定的候选FGK型贫金属星;（2）利用FGK型恒星和白色矮星的HETDEX光谱反演恒星参数，以及（3）该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识产权进行评估来支持。优点和更广泛的影响审查标准。

This research team from the University of Texas Austin and Baylor University plan a new analysis of existing observations from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) to better understand the history of star formation in the Milky Way galaxy. While HETDEX is primarily being used for the study of dark energy, the investigators have repurposed the survey for Galactic Astronomy, embodying the phrase ‘one person’s trash is another person treasure’. The investigators will work together to engage, empower, and recruit underrepresented groups in astronomy at various levels. At the undergraduate level, the investigators will focus on training underrepresented minority students through the TARUS program at UT Austin. At the community-wide level, both investigators will continue to participate in the regular outreach, e.g., by public lectures, and create a new ‘Stars of the HETDEX survey’ outreach night.The investigators will use the spectra of more than 100,000 stars observed within HETDEX to: (1) deliver atmospheric parameters for those stars, (2) use the derived atmospheric parameters to constrain the assembly of the stellar halo, and (3) conduct a deep survey of white dwarfs, the end products of a star's lifecycle, to constrain the timescale of formation. The unbiased and deep (15 G magnitude 22) nature of the HETDEX survey makes it extremely powerful in piecing together the assembly of our Galaxy when compared with other spectroscopic surveys. A pilot study of the data has indicated that radial velocities can be measured and that the spectra can be used to find metal-poor stars. The investigators will significantly expand upon this pilot study by: (1) confirming candidate FGK-type metal-poor stars identified in HETDEX using their advantaged access to higher-resolution instruments at McDonald Observatory; (2) deriving stellar parameters using the HETDEX spectra of FGK-type and White dwarf stars, and (3) using those metallicities to measure halo properties in an unbiased way.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.