Visualizing the Milky Way with SDSS (past), SEGUE (present), and LAMOST (future)
Modern, large area sky surveys allow us to build a picture of the Milky Way galaxy star by star. Until now, most research on galaxy structure and evolution has relied on observations of external galaxies, that are more easily observed in pointed observations. Although the Milky Way is in many ways more difficult to study, it is the only galaxy for which it will be possible to know the positions and velocities of the component stars in three dimensions. Past results from the Sloan Digital Sky Survey have taught us that the Milky Way is poorly described by two exponential disks with a power law density profile for spheroid stars. New density substructure continues to be discovered in the data. New results from analysis of the SEGUE spectroscopic survey of 250,000 stars, which has allowed us to trace the radial velocities of tidal debris, gives us hope that we will be able to use these tidal streams to constrain the Galactic dark matter potential. The LAMOST project in China is currently commissioning a 4m telescope with 4000 fibers (first light was October 2008). Future plans to use this telescope for a spectroscopic survey of 2.5 million Galactic stars will be described.
