Science Case and Requirements for the MOSAIC Concept for a Multi-Object Spectrograph for the European Extremely Large Telescope

TL;DR

This paper revisits science requirements for the MOSAIC multi-object spectrograph on the E-ELT, emphasizing two observational modes for diverse astronomical studies including high-redshift galaxies, stellar populations, and exoplanets.

Contribution

It provides a comprehensive update on science cases and top-level requirements for the MOSAIC instrument, integrating broad scientific input and proposing key observational modes.

Findings

Two observational modes are essential: high multiplex and high definition.

MOSAIC aims to study high-redshift galaxies, galaxy evolution, stellar populations, and exoplanets.

Next steps include detailed design and development of the instrument.

Abstract

Over the past 18 months we have revisited the science requirements for a multi-object spectrograph (MOS) for the European Extremely Large Telescope (E-ELT). These efforts span the full range of E-ELT science and include input from a broad cross-section of astronomers across the ESO partner countries. In this contribution we summarise the key cases relating to studies of high-redshift galaxies, galaxy evolution, and stellar populations, with a more expansive presentation of a new case relating to detection of exoplanets in stellar clusters. A general requirement is the need for two observational modes to best exploit the large (>40 sq. arcmin) patrol field of the E-ELT. The first mode ('high multiplex') requires integrated-light (or coarsely resolved) optical/near-IR spectroscopy of >100 objects simultaneously. The second ('high definition'), enabled by wide-field adaptive optics, requires spatially-resolved, near-IR of >10 objects/sub-fields. Within the context of the conceptual study for an ELT-MOS called MOSAIC, we summarise the top-level requirements from each case and introduce the next steps in the design process.