MOONS:a multi-object optical and near-infrared spectrograph for the VLT

Cirasuolo, Michele and Afonso, J. and Bender, R. and Bonifacio, P. and Evans, C. and Kaper, L. and Oliva, E. and Vanzi, L. and Abreu, M. and Atad-Ettedgui, E. and Babusiaux, C. and Bauer, F. and Best, P. and Bezawada, N. and Bryson, I. and Cabral, A. and Caputi, K. and Centrone, M. and Chemla, F. and Cimatti, A. and Cioni, M. R. and Clementini, G. and Coelho, J. and Daddi, E. and Dunlop, J. and Feltzing, S. and Ferguson, A. and Flores, H. and Fontana, A. and Fynbo, J. and Garilli, B. and Glauser, A. and Guinouard, I. and Hammer, F. and Hastings, P. and Hess, A. and Ivison, R. and Jagourel, P. and Jarvis, M. and Kauffman, G. and Lawrence, A. and Lee, D. and Licausi, G. and Lilly, S. and Lorenzetti, D. and Maiolino, R. and Mannucci, F. and McLure, R. and Minniti, D. and Montgomery, D. and Muschielok, B. and Nandra, K. and Navarro, R. and Norberg, P. and Origlia, L. and Padilla, N. and Peacock, J. and Pedicini, F. and Pentericci, L. and Pragt, J. and Puech, M. and Randich, S. and Renzini, A. and Ryde, N. and Rodrigues, M. and Royer, F. and Saglia, R. and Sanchez, A. and Schnetler, H. and Sobral, D. and Speziali, R. and Todd, S. and Tolstoy, E. and Torres, M. and Venema, L. and Vitali, F. and Wegner, M. and Wells, M. and Wild, V. and Wright, G. (2012) MOONS:a multi-object optical and near-infrared spectrograph for the VLT. Proceedings of SPIE, 8446. ISSN 0277-786X

Abstract

MOONS is a new conceptual design for a Multi-Object Optical and Near-infrared Spectrograph for the Very Large Telescope (VLT), selected by ESO for a Phase A study. The baseline design consists of ∼1000 fibers deployable over a field of view of ∼500 square arcmin, the largest patrol field offered by the Nasmyth focus at the VLT. The total wavelength coverage is 0.8μm-1.8μm and two resolution modes: medium resolution and high resolution. In the medium resolution mode (R∼4,000-6,000) the entire wavelength range 0.8μm-1.8μm is observed simultaneously, while the high resolution mode covers simultaneously three selected spectral regions: one around the CaII triplet (at R∼8,000) to measure radial velocities, and two regions at R∼20,000 one in the J-band and one in the H-band, for detailed measurements of chemical abundances. The grasp of the 8.2m Very Large Telescope (VLT) combined with the large multiplex and wavelength coverage of MOONS - extending into the near-IR - will provide the observational power necessary to study galaxy formation and evolution over the entire history of the Universe, from our Milky Way, through the redshift desert and up to the epoch of re-ionization at z>8-9. At the same time, the high spectral resolution mode will allow astronomers to study chemical abundances of stars in our Galaxy, in particular in the highly obscured regions of the Bulge, and provide the necessary follow-up of the Gaia mission. Such characteristics and versatility make MOONS the long-awaited workhorse near-IR MOS for the VLT, which will perfectly complement optical spectroscopy performed by FLAMES and VIMOS.