Department of Astronomy

Galactic structure and rotation

Ralph Schoenrich

Ohio State University

I will lay out different ways to determine the rotation of Galactic components. Due to their different systematics these can be played off against each other to measure the Solar motion, Galactocentric distance, and hence the circular speed of the Galactic disc at the Sun. A precise measurement of these quantities has been enabled by a new approach to statistically determine the mean distance in a sample. This approach can be extended to samples of remote stars in the Galactic halo and I will give an outline of its application.