Title: Updated optical design and trade-off study for MOONS, the Multi-Object Optical and Near Infrared spectrometer for the VLT Author: E. Oliva, S. Todd, M. Cirasuolo, H. Schnetler, D. Lunney, P. Rees, A. Bianco, E. Diolaiti, D. Ferruzzi, M. Fisher, I. Guinouard, M. Iuzzolino, I. Parry, X. Sun, A. Tozzi, F. Vitali
This paper presents the latest optical design for the MOONS triple-arm spectrographs. MOONS will be a Multi-Object Optical and Near-infrared Spectrograph and will be installed on one of the European Southern Observatory (ESO) Very Large Telescopes (VLT). Included in this paper is a trade-off analysis of different types of collimators, cameras, dichroics and filters.
Title: MOONS: a Multi-Object Optical and Near-infrared Spectrograph for the VLT Authors: M. Cirasuolo, J. Afonso, R. Bender, P. Bonifacio, C. Evans, L. Kaper, E. Oliva, L. Vanzi, M. Abreu, E. Atad-Ettedgui, C. Babusiaux, F. Bauer, P. Best, N. Bezawada, I. Bryson, A. Cabral, K. Caputi, M. Centrone, F. Chemla, A. Cimatti, M-R. Cioni, G. Clementini, J. Coelho, E. Daddi, J. Dunlop, S. Feltzing, A. Ferguson, H. Flores, A. Fontana, J. Fynbo, B. Garilli, A. Glauser, I. Guinouard, F. Hammer, P. Hastings, A. Hess, R. Ivison, P. Jagourel, M. Jarvis, G. Kauffman, A. Lawrence, D. Lee, G. Licausi, S. Lilly, D. Lorenzetti, R. Maiolino, F. Mannucci, R. McLure, D. Minniti, D. Montgomery, B. Muschielok, K. Nandra, R. Navarro, P. Norberg, L. Origlia, N. Padilla, J. Pea****, F. Pedicini, L. Pentericci, J. Pragt, M. Puech, S. Randich, A. Renzini, N. Ryde, M. Rodrigues, F. Royer, R. Saglia, A. Sanchez, et al. (12 additional authors not shown)
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 fibres 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 0.8um-1.8um and two resolution modes: medium resolution and high resolution. In the medium resolution mode (R=4,000-6,000) the entire wavelength range 0.8um-1.8um 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-ionisation 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.