The ELT-MOS (MOSAIC): towards the construction phase

TL;DR

MOSAIC is a highly versatile multi-object spectrograph for the ELT, capable of probing the early universe, galaxy evolution, dark matter, and black holes with advanced multi-IFU and MOAO technologies, ready for prompt deployment.

Contribution

This paper presents the construction phase of MOSAIC, highlighting its technical readiness, innovative capabilities, and potential scientific impact on ELT observations.

Findings

MOAO and sky subtraction with fibres demonstrated on sky

No low TRL items remaining for instrument deployment

Prompt implementation could enhance ELT robustness

Abstract

When combined with the huge collecting area of the ELT, MOSAIC will be the most effective and flexible Multi-Object Spectrograph (MOS) facility in the world, having both a high multiplex and a multi-Integral Field Unit (Multi-IFU) capability. It will be the fastest way to spectroscopically follow-up the faintest sources, probing the reionisation epoch, as well as evaluating the evolution of the dwarf mass function over most of the age of the Universe. MOSAIC will be world-leading in generating an inventory of both the dark matter (from realistic rotation curves with MOAO fed NIR IFUs) and the cool to warm-hot gas phases in z=3.5 galactic haloes (with visible wavelenth IFUs). Galactic archaeology and the first massive black holes are additional targets for which MOSAIC will also be revolutionary. MOAO and accurate sky subtraction with fibres have now been demonstrated on sky, removing all low Technical Readiness Level (TRL) items from the instrument. A prompt implementation of MOSAIC is feasible, and indeed could increase the robustness and reduce risk on the ELT, since it does not require diffraction limited adaptive optics performance. Science programmes and survey strategies are currently being investigated by the Consortium, which is also hoping to welcome a few new partners in the next two years.