The Detailed Science Case for the Maunakea Spectroscopic Explorer, 2019 edition

TL;DR

The Maunakea Spectroscopic Explorer (MSE) is a comprehensive spectroscopic platform designed to advance understanding of the faint Universe, impacting various astrophysics fields through large-scale surveys and complementing other major astronomical facilities.

Contribution

This paper presents the detailed science case for MSE, highlighting its unique capabilities and scientific goals across multiple astrophysics domains.

Findings

MSE will enable detailed chemical and dynamical studies of the Milky Way.

It will conduct revolutionary galaxy formation surveys at cosmic noon.

MSE aims to derive neutrino mass and probe inflationary physics through cosmological redshift surveys.

Abstract

(Abridged) The Maunakea Spectroscopic Explorer (MSE) is an end-to-end science platform for the design, execution and scientific exploitation of spectroscopic surveys. It will unveil the composition and dynamics of the faint Universe and impact nearly every field of astrophysics across all spatial scales, from individual stars to the largest scale structures in the Universe. Major pillars in the science program for MSE include (i) the ultimate Gaia follow-up facility for understanding the chemistry and dynamics of the distant Milky Way, including the outer disk and faint stellar halo at high spectral resolution (ii) galaxy formation and evolution at cosmic noon, via the type of revolutionary surveys that have occurred in the nearby Universe, but now conducted at the peak of the star formation history of the Universe (iii) derivation of the mass of the neutrino and insights into inflationary physics through a cosmological redshift survey that probes a large volume of the Universe with a high galaxy density. MSE is positioned to become a critical hub in the emerging international network of front-line astronomical facilities, with scientific capabilities that naturally complement and extend the scientific power of Gaia, the Large Synoptic Survey Telescope, the Square Kilometer Array, Euclid, WFIRST, the 30m telescopes and many more.