LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) — The survey's science plan

Abstract

We describe the current plans for a spectroscopic survey of millions of stars\nin the Milky Way galaxy using the Guo Shou Jing Telescope (GSJT, formerly the\nLarge Area Multi-Object Spectroscopic Telescope - LAMOST). The survey will\nobtain spectra for 2.5 million stars brighter than $r<19$ during dark/grey\ntime, and 5 million stars brighter than $r<17$ or $J<16$ on nights that are\nmoonlit or have low transparency. The survey will begin in fall of 2012, and\nwill run for at least four years. The telescope design constrains the optimal\ndeclination range for observations to $10^\\circ<\\delta<50^\\circ$, and site\nconditions lead to an emphasis on stars in the direction of the Galactic\nanticenter. The survey is divided into three parts with different target\nselection strategies: disk, anticenter, and spheroid. The resulting dataset\nwill be used to study the merger history of the Milky Way, the substructure and\nevolution of the disks, the nature of the first generation of stars through\nidentification of the lowest metallicity stars, and star formation through\nstudy of open clusters and the OB associations. Detailed design of the LEGUE\nsurvey will be completed after a review of the results of the pilot survey in\nsummer 2012.\n