The Detailed Science Case for the Maunakea Spectroscopic Explorer: the Composition and Dynamics of the Faint Universe

TL;DR

The Maunakea Spectroscopic Explorer (MSE) is a highly capable, dedicated multi-object spectroscopic observatory designed to advance diverse scientific research on the faint universe, complementing existing and future astronomical facilities.

Contribution

This paper presents a comprehensive science case for MSE, highlighting its unique capabilities and scientific goals that extend beyond current spectroscopic instruments.

Findings

MSE will enable detailed chemical and dynamical studies of faint celestial objects.

It will facilitate large-scale mapping of the interstellar and intergalactic media.

MSE is positioned as a crucial follow-up facility for major imaging surveys.

Abstract

MSE is an 11.25m aperture observatory with a 1.5 square degree field of view that will be fully dedicated to multi-object spectroscopy. More than 3200 fibres will feed spectrographs operating at low (R ~ 2000 - 3500) and moderate (R ~ 6000) spectral resolution, and approximately 1000 fibers will feed spectrographs operating at high (R ~ 40000) resolution. MSE is designed to enable transformational science in areas as diverse as tomographic mapping of the interstellar and intergalactic media; the in-situ chemical tagging of thick disk and halo stars; connecting galaxies to their large scale structure; measuring the mass functions of cold dark matter sub-halos in galaxy and cluster-scale hosts; reverberation mapping of supermassive black holes in quasars; next generation cosmological surveys using redshift space distortions and peculiar velocities. MSE is an essential follow-up facility to current and next generations of multi-wavelength imaging surveys, including LSST, Gaia, Euclid, WFIRST, PLATO, and the SKA, and is designed to complement and go beyond the science goals of other planned and current spectroscopic capabilities like VISTA/4MOST, WHT/WEAVE, AAT/HERMES and Subaru/PFS. It is an ideal feeder facility for E-ELT, TMT and GMT, and provides the missing link between wide field imaging and small field precision astronomy. MSE is optimized for high throughput, high signal-to-noise observations of the faintest sources in the Universe with high quality calibration and stability being ensured through the dedicated operational mode of the observatory. (abridged)