4MOST Consortium Survey 3: Milky Way Disc and Bulge Low-Resolution Survey (4MIDABLE-LR)

TL;DR

The 4MIDABLE-LR survey aims to map the Milky Way's disc and bulge in unprecedented detail by combining low-resolution spectroscopy with Gaia data, enabling insights into the Galaxy's formation and evolution.

Contribution

It introduces a large-scale, detailed kinematic and chemical survey of the Milky Way's disc and bulge, leveraging Gaia data for target selection and tailored sub-surveys for specific scientific goals.

Findings

Largest Gaia follow-up survey down to G=19 mag.

Detailed map of the Milky Way's chemo-kinematical structure.

Enhanced understanding of the Galaxy's assembly and evolution.

Abstract

The mechanisms of the formation and evolution of the Milky Way are encoded in the orbits, chemistry and ages of its stars. With the 4MOST MIlky way Disk And BuLgE Low-Resolution Survey (4MIDABLE-LR) we aim to study kinematic and chemical substructures in the Milky Way disc and bulge region with samples of unprecedented size out to larger distances and greater precision than conceivable with Gaia alone or any other ongoing or planned survey. Gaia gives us the unique opportunity for target selection based almost entirely on parallax and magnitude range, hence increasing the efficiency in sampling larger Milky Way volumes with well-defined and effective selection functions. Our main goal is to provide a detailed chrono-chemo-kinematical extended map of our Galaxy and the largest Gaia follow-up down to $G = 19$ magnitudes (Vega). The complex nature of the disc components (for example, large target densities and highly structured extinction distribution in the Milky Way bulge and disc area), prompted us to develop a survey strategy with five main sub-surveys that are tailored to answer the still open questions about the assembly and evolution of our Galaxy, while taking full advantage of the Gaia data.