This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Dr Wyse will investigate the early phases of evolution of the Milky Way's thin disk and the formation of its thick disk by using stellar spectra from the Radial Velocity Experiment (RAVE). This survey uses a fiber-fed spectrograph on the 1.2-meter UK Schmidt Telescope to obtain spectra of 150 stars at a time. From these, she will measure the star's motion towards or away from us, and estimate its surface gravity and temperature, chemical abundances and stellar rotation. A graduate student will travel each year to Australia to make observations for RAVE. One student will study a sample that may represent the first stars in the Milky Way's disk; they will be selected from RAVE to have a low metal abundance (below one-tenth of the Sun's value), but to follow the near-circular orbits characteristic of disk stars. High-resolution spectra will be taken to obtain more precise chemical abundances. A second student will use the detailed pattern of element abundances to test whether these stars could have been born in satellite galaxies that were swallowed by the Milky Way, and to develop a model for early disk formation.
This award will support two graduate students. The RAVE database will be a widely useful resource across the astronomical community. The collaboration will release its database in a form that is compliant with the standards of the Virtual Astronomical Observatory, making it accessible to the community.
