Mapping the Milky Way with SDSS, Gaia and LSST

We summarize recent work on the Milky Way “tomography” with SDSS and use these results to illustrate what further breakthroughs can be expect from Gaia and the Large Synoptic Survey Telescope (LSST). LSST is the most ambitious ground-based survey currently planned in the visible band. Mapping of the Milky Way is one of the four main science and design drivers. The main 20 000 deg2 . survey area will be imaged about 1000 times in six bands (ugrizy) during the anticipated 10 years of operations, with the first light expected in 2015. Due to Gaia’s superb astrometric and photometric accuracy, and LSST’s significantly deeper data, the two surveys are highly complementary: Gaia will map the Milky Way’s disk with unprecedented detail, and LSST will extend this map all the way to the halo’s edge.