The Maunakea Spectroscopic Explorer: Thousands of Fibers, Infinite Possibilities

Abstract: The Maunakea Spectroscopic Explorer (MSE) is a massively multiplexed spectroscopic survey facility that will replace the Canada-France-Hawaii Telescope over the next two decades. This 12.5-meter telescope, with its 1.5 square degree field-of-view, will observe 18,000-20,000 astronomical targets in every pointing from 0.36-1.80 microns at low/moderate resolution (R~3,000, 6,000) and from 0.36-0.90 microns at high resolution (R~30,000). Parallel positioning of all fibers in the field will occur, providing simultaneous full-field coverage for both resolution modes. Unveiling the composition and dynamics of the faint Universe, MSE will impact nearly every field of astrophysics across all spatial scales, from individual stars to the largest scale structures in the Universe, including (i) the ultimate Gaia follow-up facility for understanding the chemistry and dynamics of the distant Milky Way, including the distant halo at high spectral resolution, (ii) the unparalleled study of galaxy formation and evolution at cosmic noon, (iii) the determination of the neutrino mass, and (iv) the generation of insights into inflationary physics through a cosmological redshift survey that probes a large volume of the Universe with a high galaxy density. Initially, CFHT will build a Pathfinder instrument to fast-track the development of MSE technology while providing multi-object and IFU spectroscopic capability.