Validation of the Scientific Program for the Dark Energy Spectroscopic Instrument

Published version
Repository DOI

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Authors
Adame, AG 
Aguilar, J 
Aldering, G 
Abstract

jats:titleAbstract</jats:title> jats:pThe Dark Energy Spectroscopic Instrument (DESI) was designed to conduct a survey covering 14,000 degjats:sup2</jats:sup> over 5 yr to constrain the cosmic expansion history through precise measurements of baryon acoustic oscillations (BAO). The scientific program for DESI was evaluated during a 5 month survey validation (SV) campaign before beginning full operations. This program produced deep spectra of tens of thousands of objects from each of the stellar Milky Way Survey (MWS), Bright Galaxy Survey (BGS), luminous red galaxy (LRG), emission line galaxy (ELG), and quasar target classes. These SV spectra were used to optimize redshift distributions, characterize exposure times, determine calibration procedures, and assess observational overheads for the 5 yr program. In this paper, we present the final target selection algorithms, redshift distributions, and projected cosmology constraints resulting from those studies. We also present a One-Percent Survey conducted at the conclusion of SV covering 140 degjats:sup2</jats:sup> using the final target selection algorithms with exposures of a depth typical of the main survey. The SV indicates that DESI will be able to complete the full 14,000 degjats:sup2</jats:sup> program with spectroscopically confirmed targets from the MWS, BGS, LRG, ELG, and quasar programs with total sample sizes of 7.2, 13.8, 7.46, 15.7, and 2.87 million, respectively. These samples will allow exploration of the Milky Way halo, clustering on all scales, and BAO measurements with a statistical precision of 0.28% over the redshift interval jats:italicz</jats:italic> < 1.1, 0.39% over the redshift interval 1.1 < jats:italicz</jats:italic> < 1.9, and 0.46% over the redshift interval 1.9 < jats:italicz</jats:italic> < 3.5.</jats:p>

Description
Keywords
Cosmology, Redshift surveys
Journal Title
The Astronomical Journal
Conference Name
Journal ISSN
0004-6256
1538-3881
Volume Title
167
Publisher
American Astronomical Society
Sponsorship
DOE ∣ Office of Science (SC) (DE-AC02-05CH11231)
National Energy Research Scientific Computing Center (NERSC) (DE-AC02-05CH11231)
National Optical-Infrared Astronomy Research Laboratory (AST-0950945)