Overview of the instrumentation for the Dark Energy Spectroscopic Instrument
Abstract
The Dark Energy Spectroscopic Instrument (DESI) embarked on an ambitious 5 yr survey in 2021 May to explore the nature of dark energy with spectroscopic measurements of 40 million galaxies and quasars. DESI will determine precise redshifts and employ the baryon acoustic oscillation method to measure distances from the nearby universe to beyond redshift z > 3.5, and employ redshift space distortions to measure the growth of structure and probe potential modifications to general relativity. We describe the significant instrumentation we developed to conduct the DESI survey. This includes: a wide-field, 3.°2 diameter prime-focus corrector; a focal plane system with 5020 fiber positioners on the 0.812 m diameter, aspheric focal surface; 10 continuous, high-efficiency fiber cable bundles that connect the focal plane to the spectrographs; and 10 identical spectrographs. Each spectrograph employs a pair of dichroics to split the light into three channels that together record the light from 360–980 nm with a spectral resolution that ranges from 2000–5000. We describe the science requirements, their connection to the technical requirements, the management of the project, and interfaces between subsystems. DESI was installed at the 4 m Mayall Telescope at Kitt Peak National Observatory and has achieved all of its performance goals. Some performance highlights include an rms positioner accuracy of better than 0.″1 and a median signal-to-noise ratio of 7 of the [O ii] doublet at 8 × 10−17 erg s−1 cm−2 in 1000 s for galaxies at z = 1.4–1.6. We conclude with additional highlights from the on-sky validation and commissioning, key successes, and lessons learned.
Citation
DESI Collaboration , Abareshi , B , Aguilar , J , Ahlen , S , Alam , S , Alexander , D M , Alfarsy , R , Allen , L , Prieto , C A , Alves , O , Ameel , J , Armengaud , E , Asorey , J , Aviles , A , Bailey , S , Balaguera-Antolínez , A , Ballester , O , Baltay , C , Bault , A , Beltran , S F , Benavides , B , BenZvi , S , Berti , A , Besuner , R , Beutler , F , Bianchi , D , Blake , C , Blanc , P , Blum , R , Bolton , A , Bose , S , Bramall , D , Brieden , S , Brodzeller , A , Brooks , D , Brownewell , C , Buckley-Geer , E , Cahn , R N , Cai , Z , Canning , R , Capasso , R , Rosell , A C , Carton , P , Casas , R , Castander , F J , Cervantes-Cota , J L , Chabanier , S , Chaussidon , E , Chuang , C & Tojeiro , R 2022 , ' Overview of the instrumentation for the Dark Energy Spectroscopic Instrument ' , Astronomical Journal , vol. 164 , no. 5 , 207 . https://doi.org/10.3847/1538-3881/ac882b
Publication
Astronomical Journal
Status
Peer reviewed
ISSN
1538-3881Type
Journal article
Rights
Copyright © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Description
Funding: This research is supported by the Director, Office of Science, Office of High Energy Physics of the U.S. Department of Energy under contract No. DE-AC02-05CH11231, and by the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility under the same contract. Additional support for DESI is provided by the U.S. National Science Foundation, Division of Astronomical Sciences under contract No. AST-0950945 to the NSFʼs National Optical Infrared Astronomy Research Laboratory; the Science and Technologies Facilities Council of the United Kingdom; the Gordon and Betty Moore Foundation; the Heising–Simons Foundation; the French Alternative Energies and Atomic Energy Commission (CEA); the National Council of Science and Technology of Mexico (CONACYT); the Ministry of Science and Innovation of Spain, and by the DESI Member Institutions.Collections
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