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

点击翻译按钮获取中文摘要

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.