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

TL;DR

The LEGUE survey plans to spectroscopically observe millions of stars in the Milky Way using LAMOST, aiming to understand galactic structure, formation history, and stellar populations over four years.

Contribution

This paper outlines the detailed survey plan for LEGUE, including target selection, observational strategy, and scientific goals, which is a significant expansion of galactic spectroscopic data collection.

Findings

Survey will obtain spectra for 2.5 million stars brighter than r<19.

Targeting stars in the Galactic anticenter region.

Aims to study Milky Way's merger history and stellar populations.

Abstract

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