The DESI survey validation : results from visual inspection of bright galaxies, luminous red galaxies, and emission line galaxies
Abstract
The Dark Energy Spectroscopic Instrument (DESI) Survey has obtained a set of spectroscopic measurements of galaxies for validating the final survey design and target selections. To assist these tasks, we visually inspect (VI) DESI spectra of approximately 2,500 bright galaxies, 3,500 luminous red galaxies, and 10,000 emission line galaxies, to obtain robust redshift identifications. We then utilize the VI redshift information to characterize the performance of the DESI operation. Based on the VI catalogs, our results show that the final survey design yields samples of bright galaxies, luminous red galaxies, and emission line galaxies with purity greater than 99%. Moreover, we demonstrate that the precision of the redshift measurements is approximately 10 km/s for bright galaxies and emission line galaxies and approximately 40 km/s for luminous red galaxies. The average redshift accuracy is within 10 km/s for the three types of galaxies. The VI process also helps to improve the quality of the DESI data by identifying spurious spectral features introduced by the pipeline. Finally, we show examples of unexpected real astronomical objects, such as Lyman α emitters and strong lensing candidates, identified by VI. These results demonstrate the importance and utility of visually inspecting data from incoming and upcoming surveys, especially during their early operation phases.
Citation
Lan , T-W , Tojeiro , R , Armengaud , E , Prochaska , J X , Davis , T M , Alexander , D M , Raichoor , A , Zhou , R , Yeche , C , Balland , C , BenZvi , S , Berti , A , Canning , R , Carr , A , Chittenden , H , Cole , S , Cousinou , M-C , Dawson , K , Dey , B , Douglass , K , Edge , A , Escoffier , S , Glanville , A , Gontcho , S G A , Guy , J , Hahn , C , Howlett , C , Hwang , H S , Jiang , L , Kovacs , A , Mezcua , M , Moore , S , Nadathur , S , Oh , M , Parkinson , D , Rocher , A , Ross , A J , Ruhlmann-Kleider , V , Sabiu , C G , Said , K , Saulder , C , Sierra-Porta , D , Weiner , B , Yu , J , Zarrouk , P , Zhang , Y , Zou , H , Ahlen , S , Bailey , S , Brooks , D , Cooper , A P , de la Macorra , A , Dey , A , Dhungana , G , Doel , P , Eftekharzadeh , S , Fanning , K , Font-Ribera , A , Garrison , L , Gaztanaga , E , Kehoe , R , Kisner , T , Kremin , A , Landriau , M , Le Guillou , L , Levi , M E , Magneville , C , Meisner , A M , Miquel , R , Moustakas , J , Myers , A D , Newman , J A , Nie , J D , Palanque-Delabrouille , N , Percival , W J , Poppett , C , Prada , F , Schubnell , M , Tarle , G , Weaver , B A , Zhang , K & Zhou , Z 2023 , ' The DESI survey validation : results from visual inspection of bright galaxies, luminous red galaxies, and emission line galaxies ' , Astrophysical Journal , vol. 943 , no. 1 , 68 . https://doi.org/10.3847/1538-4357/aca5fa
Publication
Astrophysical Journal
Status
Peer reviewed
ISSN
0004-637XType
Journal article
Rights
Copyright © 2023. 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: TWL was supported by the Ministry of Science and Technology (MOST 111-2112-M-002-015-MY3), the Ministry of Education, Taiwan (MOE Yushan Young Scholar grant NTU-110VV007), National Taiwan University research grants (NTU CC-111L894806, NTU- 111L7318), and NSF grant AST-1911140. DMA acknowledges the Science Technology and Facilities Council (STFC) for support through grant code ST/T000244/1. 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 NSF’s 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 (MICINN), and by the DESI Member Institutions: https://www.desi.lbl.gov/ collaborating-institutions.Collections
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