Mapping Milky Way And Local Volume Structure With LSST

The LSST will yield revolutionary, multi-dimensional maps of the Milky Way (MW) galaxy and its neighbors. With its planned 1000 epochs over 6 bands and a final limiting magnitude of r=27.5 (AB mag; 5-sigma), it will provide an excellent resource for mapping the structure and accretion history of the MW and beyond in a way that the present generation of surveys can only hint at. LSST is expected to catalog 10 billion stars, including photometric metallicities for the 200 million F/G stars within 100 kpc and map the tangential velocity field of stars bright than r=24 mag to at least 10 kpc (at 10 km/s precision) and as far as 25 kpc (at 60 km/s precision). Specific related science to be enabled by LSST includes: mapping the 3D distribution of dust in the MW's disk, including variations in RV; understanding the smooth distribution of stars in the MW and other nearby galaxies; understanding large-scale chemical gradients in the MW; discovering lumps and streams in metallicity and phase-space; inferring the mass distribution in the MW; discovering ultra-faint galaxies throughout the Local Volume....