MOONS Surveys of the Milky Way and its Satellites

TL;DR

The MOONS survey utilizes a powerful infrared multi-object spectrograph on the VLT to study stellar populations in the Milky Way and its satellites, providing detailed chemo-dynamical data to understand galaxy formation.

Contribution

This paper introduces the MOONS instrument and its capabilities for large-scale stellar spectroscopy in the Milky Way and Local Group galaxies.

Findings

Sampling of millions of stars over the galaxy's dense regions.

High-resolution spectroscopy enables detailed chemical abundance analysis.

Simultaneous optical and near-infrared observations enhance data richness.

Abstract

The study of resolved stellar populations in the Milky Way and other Local Group galaxies can provide us with a fossil record of their chemo-dynamical and star-formation histories over timescales of many billions of years. In the galactic components and stellar systems of the Milky Way and its satellites, individual stars can be resolved. Therefore, they represent a unique laboratory in which to investigate the details of the processes behind the formation and evolution of the disc and dwarf/irregular galaxies. MOONS at the VLT represents a unique combination of an efficient infrared multi-object spectrograph and a large-aperture 8-m-class telescope which will sample the cool stellar populations of the dense central regions of the Milky Way and its satellites, delivering accurate radial velocities, metallicities, and other chemical abundances for several millions of stars over its lifetime (see Cirasuolo et al., this issue). MOONS will observe up to 1000 targets across a 25-arcminute field of view in the optical and near-infrared (0.6-1.8 micron) simultaneously. A high-resolution (R~19700) setting in the H band has been designed for the accurate determination of stellar abundances such as alpha, light, iron-peak and neutron-capture elements.