Collaborative Research: Kinematics and Chemistry of M33- Determining the Past, Present and Future of the M31/M33 system

Johns Hopkins University, Baltimore MD

Investigators

Abstract

This project will use the Keck telescope to study individual stars in M33, a companion galaxy to the Andromeda galaxy (M31). Using spectroscopy, they will obtain information about the motion and star formation history of the disk and potential halo of M33. They will use this information to learn if its interactions with M31 have influenced its evolution. The science program is integrated with a high school research program that will introduce students to cutting-edge research on M33's formation history. With a mass ten times lower than M31's and a star formation rate 10 times higher, M33 is the best local analog for high z galaxies. Spectroscopic observations of resolved stars in M31 will provide measurements of the line-of-sight stellar velocities and dispersion and quantitative comparisons of the dynamics of the stellar and gas disk components. It will also produce the first iron and alpha-element abundance distributions for stars in M33. Finally, it will definitively determine of M33 has a stellar halo. This chemo-dynamical analysis will provide critical observational constraints on internal and external heating mechanisms affecting low-mass stellar disks. It will also constrain models of M33's orbit around M31, yielding insights into whether M33 is on first infall or has interacted substantially with M31 in the past. 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.