Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument

DESI Collaboration

doi:10.3847/1538-3881/ac882b

Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument

DESI Collaboration

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

Abstract / Description of output

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, 32 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 01 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.

Original language	English
Article number	207
Pages (from-to)	1-62
Number of pages	62
Journal	Astronomical Journal
Volume	164
Issue number	5
DOIs	https://doi.org/10.3847/1538-3881/ac882b
Publication status	Published - 20 Oct 2022

Keywords / Materials (for Non-textual outputs)

astro-ph.IM
astro-ph.CO

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10.3847/1538-3881/ac882bLicence: Creative Commons: Attribution (CC-BY)

Abareshi_2022_AJ_164_207Final published version, 17.8 MBLicence: CC BY

https://arxiv.org/abs/2205.10939Licence: Creative Commons: Attribution (CC-BY)

Cite this

@article{8294d2bc3bfd4929bfd0f5ba7e00a3ed,

title = "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, 32 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 01 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.",

keywords = "astro-ph.IM, astro-ph.CO",

author = "{DESI Collaboration} and B. Abareshi and J. Aguilar and S. Ahlen and Shadab Alam and Alexander, {David M.} and R. Alfarsy and L. Allen and Prieto, {C. Allende} and O. Alves and J. Ameel and E. Armengaud and J. Asorey and Alejandro Aviles and S. Bailey and A. Balaguera-Antol{\'i}nez and O. Ballester and C. Baltay and A. Bault and Beltran, {S. F.} and B. Benavides and S. BenZvi and A. Berti and R. Besuner and Florian Beutler and D. Bianchi and C. Blake and P. Blanc and R. Blum and A. Bolton and S. Bose and D. Bramall and S. Brieden and A. Brodzeller and D. Brooks and C. Brownewell and E. Buckley-Geer and Cahn, {R. N.} and Z. Cai and R. Canning and Rosell, {A. Carnero} and P. Carton and R. Casas and Castander, {F. J.} and Cervantes-Cota, {J. L.} and S. Chabanier and E. Chaussidon and C. Chuang and C. Circosta and S. Cole and Cooper, {A. P.} and Costa, {L. da} and Cousinou, {M. -C.} and A. Cuceu and Davis, {T. M.} and K. Dawson and Cruz-Noriega, {R. de la} and Macorra, {A. de la} and Mattia, {A. de} and Costa, {J. Della} and P. Demmer and M. Derwent and A. Dey and B. Dey and G. Dhungana and Z. Ding and C. Dobson and P. Doel and J. Donald-McCann and J. Donaldson and K. Douglass and Y. Duan and P. Dunlop and J. Edelstein and S. Eftekharzadeh and Eisenstein, {D. J.} and M. Enriquez-Vargas and S. Escoffier and M. Evatt and P. Fagrelius and X. Fan and K. Fanning and Fawcett, {V. A.} and S. Ferraro and J. Ereza and B. Flaugher and A. Font-Ribera and Forero-Romero, {J. E.} and Frenk, {C. S.} and S. Fromenteau and G{\"a}nsicke, {B. T.} and C. Garcia-Quintero and L. Garrison and E. Gazta{\~n}aga and F. Gerardi and H. Gil-Mar{\'i}n and Gontcho, {S. Gontcho A} and Gonzalez-Morales, {Alma X.} and G. Gonzalez-de-Rivera and V. Gonzalez-Perez and C. Gordon and O. Graur and D. Green and C. Grove and D. Gruen and G. Gutierrez and J. Guy and C. Hahn and S. Harris and D. Herrera and Herrera-Alcantar, {Hiram K.} and K. Honscheid and C. Howlett and D. Huterer and V. Ir{\v s}i{\v c} and M. Ishak and P. Jelinsky and L. Jiang and J. Jimenez and Jing, {Y. P.} and R. Joyce and E. Jullo and S. Juneau and Kara{\c c}aylı, {N. G.} and M. Karamanis and A. Karcher and T. Karim and R. Kehoe and S. Kent and D. Kirkby and T. Kisner and F. Kitaura and Koposov, {S. E.} and A. Kov{\'a}cs and A. Kremin and Alex Krolewski and B. L'Huillier and O. Lahav and A. Lambert and C. Lamman and Ting-Wen Lan and M. Landriau and S. Lane and D. Lang and Lange, {J. U.} and J. Lasker and Guillou, {L. Le} and A. Leauthaud and Suu, {A. Le Van} and Levi, {Michael E.} and Li, {T. S.} and C. Magneville and M. Manera and Manser, {Christopher J.} and B. Marshall and W. McCollam and P. McDonald and Meisner, {Aaron M.} and Mezcua, {J. Mena-Fern{\'a}ndez M.} and T. Miller and R. Miquel and P. Montero-Camacho and J. Moon and Martini, {J. Paul} and J. Meneses-Rizo and J. Moustakas and E. Mueller and Andrea Mu{\~n}oz-Guti{\'e}rrez and Myers, {Adam D.} and S. Nadathur and J. Najita and L. Napolitano and E. Neilsen and Newman, {Jeffrey A.} and Nie, {J. D.} and Y. Ning and G. Niz and P. Norberg and Noriega, {Hern{\'a}n E.} and T. O'Brien and A. Obuljen and N. Palanque-Delabrouille and A. Palmese and P. Zhiwei and D. Pappalardo and X. Peng and Percival, {W. J.} and S. Perruchot and R. Pogge and C. Poppett and A. Porredon and F. Prada and J. Prochaska and R. Pucha and A. P{\'e}rez-Fern{\'a}ndez and I. P{\'e}rez-R{\'a}fols and D. Rabinowitz and A. Raichoor and S. Ramirez-Solano and C{\'e}sar Ram{\'i}rez-P{\'e}rez and C. Ravoux and K. Reil and M. Rezaie and A. Rocher and C. Rockosi and Roe, {N. A.} and A. Roodman and Ross, {A. J.} and G. Rossi and R. Ruggeri and V. Ruhlmann-Kleider and Sabiu, {C. G.} and S. Safonova and K. Said and A. Saintonge and Catonga, {Javier Salas} and L. Samushia and E. Sanchez and C. Saulder and E. Schaan and E. Schlafly and D. Schlegel and J. Schmoll and D. Scholte and M. Schubnell and A. Secroun and H. Seo and S. Serrano and Sharples, {Ray M.} and Sholl, {Michael J.} and Silber, {Joseph Harry} and Silva, {D. R.} and M. Sirk and M. Siudek and A. Smith and D. Sprayberry and R. Staten and B. Stupak and T. Tan and Gregory Tarl{\'e} and Tie, {Suk Sien} and R. Tojeiro and Ure{\~n}a-L{\'o}pez, {L. A.} and F. Valdes and O. Valenzuela and M. Valluri and M. Vargas-Maga{\~n}a and L. Verde and M. Walther and B. Wang and Wang, {M. S.} and Weaver, {B. A.} and C. Weaverdyck and R. Wechsler and Wilson, {Michael J.} and J. Yang and Y. Yu and S. Yuan and Christophe Y{\`e}che and H. Zhang and K. Zhang and Cheng Zhao and Rongpu Zhou and Zhimin Zhou and J. Zou and J. Zou and S. Zou and Y. Zu",

note = "78 pages, 32 figures, submitted to AJ Funding Information: The formal start of the project that became DESI occurred with DOE approval of Critical Decision Zero (CD-0) or Mission Need on 2012 September 18. DOE subsequently selected Lawrence Berkeley National Laboratory (LBNL) as the lead laboratory for DESI and appointed the LBNL Project Director. Extensive design studies began at this time and showed that the instrument would need an FOV of 2°–3° diameter, many thousands of fiber positioners, high throughput, and excellent PSF stability for sky subtraction. This period also coincided with significant research and development (R&D) and systems engineering activity. The R&D included the development of fiber positioners, study of alternative positioner technologies, work on spectrograph PSF stability that would be critical for sky subtraction, and further development of low-noise amplifiers for the CCDs. During this time period, we had many conversations with vendors about the corrector lenses, spectrograph optics, and VPH gratings. We also received generous support from the Gordon and Betty Moore Foundation and the Heising–Simons Foundation. This early financial support enabled us to begin procurements of critical, long-lead components, namely the glass for the corrector and the first spectrograph. Funding Information: 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, and by the DESI Member Institutions: Aix-Marseille University; Argonne National Laboratory; Barcelona-Madrid Regional Participation Group; Brookhaven National Laboratory; Boston University; Brazil Regional Participation Group; Carnegie Mellon University; CEA-IRFU, Saclay; China Participation Group; Cornell University; Durham University; {\'E}cole Polytechnique F{\'e}d{\'e}rale de Lausanne; Eidgen{\"o}ssische Technische Hochschule, Z{\"u}rich; Fermi National Accelerator Laboratory; Granada-Madrid-Tenerife Regional Participation Group; Harvard University; Kansas State University; Korea Astronomy and Space Science Institute; Korea Institute for Advanced Study; Lawrence Berkeley National Laboratory; Laboratoire de Physique Nucl{\'e}aire et de Hautes Energies; Ludwig Maximilians University; Max Planck Institute; Mexico Regional Participation Group; New York University; NSF's National Optical-Infrared Astronomy Research Laboratory; Ohio University; Perimeter Institute; Shanghai Jiao Tong University; Siena College; SLAC National Accelerator Laboratory; Southern Methodist University; Swinburne University; The Ohio State University; Universidad de los Andes; University of Arizona; University of Barcelona; University of California, Berkeley; University of California, Irvine; University of California, Santa Cruz; University College London; University of Florida; University of Michigan at Ann Arbor; University of Pennsylvania; University of Pittsburgh; University of Portsmouth; University of Queensland; University of Rochester; University of Toronto; University of Utah; University of Waterloo; University of Wyoming; University of Zurich; UK Regional Participation Group; and Yale University. Publisher Copyright: {\textcopyright} 2022. The Author(s). Published by the American Astronomical Society.",

year = "2022",

month = oct,

day = "20",

doi = "10.3847/1538-3881/ac882b",

language = "English",

volume = "164",

pages = "1--62",

journal = "Astronomical Journal",

issn = "0004-6256",

publisher = "IOP Publishing",

number = "5",

}

TY - JOUR

T1 - Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument

AU - DESI Collaboration

AU - Abareshi, B.

AU - Aguilar, J.

AU - Ahlen, S.

AU - Alam, Shadab

AU - Alexander, David M.

AU - Alfarsy, R.

AU - Allen, L.

AU - Prieto, C. Allende

AU - Alves, O.

AU - Ameel, J.

AU - Armengaud, E.

AU - Asorey, J.

AU - Aviles, Alejandro

AU - Bailey, S.

AU - Balaguera-Antolínez, A.

AU - Ballester, O.

AU - Baltay, C.

AU - Bault, A.

AU - Beltran, S. F.

AU - Benavides, B.

AU - BenZvi, S.

AU - Berti, A.

AU - Besuner, R.

AU - Beutler, Florian

AU - Bianchi, D.

AU - Blake, C.

AU - Blanc, P.

AU - Blum, R.

AU - Bolton, A.

AU - Bose, S.

AU - Bramall, D.

AU - Brieden, S.

AU - Brodzeller, A.

AU - Brooks, D.

AU - Brownewell, C.

AU - Buckley-Geer, E.

AU - Cahn, R. N.

AU - Cai, Z.

AU - Canning, R.

AU - Rosell, A. Carnero

AU - Carton, P.

AU - Casas, R.

AU - Castander, F. J.

AU - Cervantes-Cota, J. L.

AU - Chabanier, S.

AU - Chaussidon, E.

AU - Chuang, C.

AU - Circosta, C.

AU - Cole, S.

AU - Cooper, A. P.

AU - Costa, L. da

AU - Cousinou, M. -C.

AU - Cuceu, A.

AU - Davis, T. M.

AU - Dawson, K.

AU - Cruz-Noriega, R. de la

AU - Macorra, A. de la

AU - Mattia, A. de

AU - Costa, J. Della

AU - Demmer, P.

AU - Derwent, M.

AU - Dey, A.

AU - Dey, B.

AU - Dhungana, G.

AU - Ding, Z.

AU - Dobson, C.

AU - Doel, P.

AU - Donald-McCann, J.

AU - Donaldson, J.

AU - Douglass, K.

AU - Duan, Y.

AU - Dunlop, P.

AU - Edelstein, J.

AU - Eftekharzadeh, S.

AU - Eisenstein, D. J.

AU - Enriquez-Vargas, M.

AU - Escoffier, S.

AU - Evatt, M.

AU - Fagrelius, P.

AU - Fan, X.

AU - Fanning, K.

AU - Fawcett, V. A.

AU - Ferraro, S.

AU - Ereza, J.

AU - Flaugher, B.

AU - Font-Ribera, A.

AU - Forero-Romero, J. E.

AU - Frenk, C. S.

AU - Fromenteau, S.

AU - Gänsicke, B. T.

AU - Garcia-Quintero, C.

AU - Garrison, L.

AU - Gaztañaga, E.

AU - Gerardi, F.

AU - Gil-Marín, H.

AU - Gontcho, S. Gontcho A

AU - Gonzalez-Morales, Alma X.

AU - Gonzalez-de-Rivera, G.

AU - Gonzalez-Perez, V.

AU - Gordon, C.

AU - Graur, O.

AU - Green, D.

AU - Grove, C.

AU - Gruen, D.

AU - Gutierrez, G.

AU - Guy, J.

AU - Hahn, C.

AU - Harris, S.

AU - Herrera, D.

AU - Herrera-Alcantar, Hiram K.

AU - Honscheid, K.

AU - Howlett, C.

AU - Huterer, D.

AU - Iršič, V.

AU - Ishak, M.

AU - Jelinsky, P.

AU - Jiang, L.

AU - Jimenez, J.

AU - Jing, Y. P.

AU - Joyce, R.

AU - Jullo, E.

AU - Juneau, S.

AU - Karaçaylı, N. G.

AU - Karamanis, M.

AU - Karcher, A.

AU - Karim, T.

AU - Kehoe, R.

AU - Kent, S.

AU - Kirkby, D.

AU - Kisner, T.

AU - Kitaura, F.

AU - Koposov, S. E.

AU - Kovács, A.

AU - Kremin, A.

AU - Krolewski, Alex

AU - L'Huillier, B.

AU - Lahav, O.

AU - Lambert, A.

AU - Lamman, C.

AU - Lan, Ting-Wen

AU - Landriau, M.

AU - Lane, S.

AU - Lang, D.

AU - Lange, J. U.

AU - Lasker, J.

AU - Guillou, L. Le

AU - Leauthaud, A.

AU - Suu, A. Le Van

AU - Levi, Michael E.

AU - Li, T. S.

AU - Magneville, C.

AU - Manera, M.

AU - Manser, Christopher J.

AU - Marshall, B.

AU - McCollam, W.

AU - McDonald, P.

AU - Meisner, Aaron M.

AU - Mezcua, J. Mena-Fernández M.

AU - Miller, T.

AU - Miquel, R.

AU - Montero-Camacho, P.

AU - Moon, J.

AU - Martini, J. Paul

AU - Meneses-Rizo, J.

AU - Moustakas, J.

AU - Mueller, E.

AU - Muñoz-Gutiérrez, Andrea

AU - Myers, Adam D.

AU - Nadathur, S.

AU - Najita, J.

AU - Napolitano, L.

AU - Neilsen, E.

AU - Newman, Jeffrey A.

AU - Nie, J. D.

AU - Ning, Y.

AU - Niz, G.

AU - Norberg, P.

AU - Noriega, Hernán E.

AU - O'Brien, T.

AU - Obuljen, A.

AU - Palanque-Delabrouille, N.

AU - Palmese, A.

AU - Zhiwei, P.

AU - Pappalardo, D.

AU - Peng, X.

AU - Percival, W. J.

AU - Perruchot, S.

AU - Pogge, R.

AU - Poppett, C.

AU - Porredon, A.

AU - Prada, F.

AU - Prochaska, J.

AU - Pucha, R.

AU - Pérez-Fernández, A.

AU - Pérez-Ráfols, I.

AU - Rabinowitz, D.

AU - Raichoor, A.

AU - Ramirez-Solano, S.

AU - Ramírez-Pérez, César

AU - Ravoux, C.

AU - Reil, K.

AU - Rezaie, M.

AU - Rocher, A.

AU - Rockosi, C.

AU - Roe, N. A.

AU - Roodman, A.

AU - Ross, A. J.

AU - Rossi, G.

AU - Ruggeri, R.

AU - Ruhlmann-Kleider, V.

AU - Sabiu, C. G.

AU - Safonova, S.

AU - Said, K.

AU - Saintonge, A.

AU - Catonga, Javier Salas

AU - Samushia, L.

AU - Sanchez, E.

AU - Saulder, C.

AU - Schaan, E.

AU - Schlafly, E.

AU - Schlegel, D.

AU - Schmoll, J.

AU - Scholte, D.

AU - Schubnell, M.

AU - Secroun, A.

AU - Seo, H.

AU - Serrano, S.

AU - Sharples, Ray M.

AU - Sholl, Michael J.

AU - Silber, Joseph Harry

AU - Silva, D. R.

AU - Sirk, M.

AU - Siudek, M.

AU - Smith, A.

AU - Sprayberry, D.

AU - Staten, R.

AU - Stupak, B.

AU - Tan, T.

AU - Tarlé, Gregory

AU - Tie, Suk Sien

AU - Tojeiro, R.

AU - Ureña-López, L. A.

AU - Valdes, F.

AU - Valenzuela, O.

AU - Valluri, M.

AU - Vargas-Magaña, M.

AU - Verde, L.

AU - Walther, M.

AU - Wang, B.

AU - Wang, M. S.

AU - Weaver, B. A.

AU - Weaverdyck, C.

AU - Wechsler, R.

AU - Wilson, Michael J.

AU - Yang, J.

AU - Yu, Y.

AU - Yuan, S.

AU - Yèche, Christophe

AU - Zhang, H.

AU - Zhang, K.

AU - Zhao, Cheng

AU - Zhou, Rongpu

AU - Zhou, Zhimin

AU - Zou, J.

AU - Zou, S.

AU - Zu, Y.

N1 - 78 pages, 32 figures, submitted to AJ Funding Information: The formal start of the project that became DESI occurred with DOE approval of Critical Decision Zero (CD-0) or Mission Need on 2012 September 18. DOE subsequently selected Lawrence Berkeley National Laboratory (LBNL) as the lead laboratory for DESI and appointed the LBNL Project Director. Extensive design studies began at this time and showed that the instrument would need an FOV of 2°–3° diameter, many thousands of fiber positioners, high throughput, and excellent PSF stability for sky subtraction. This period also coincided with significant research and development (R&D) and systems engineering activity. The R&D included the development of fiber positioners, study of alternative positioner technologies, work on spectrograph PSF stability that would be critical for sky subtraction, and further development of low-noise amplifiers for the CCDs. During this time period, we had many conversations with vendors about the corrector lenses, spectrograph optics, and VPH gratings. We also received generous support from the Gordon and Betty Moore Foundation and the Heising–Simons Foundation. This early financial support enabled us to begin procurements of critical, long-lead components, namely the glass for the corrector and the first spectrograph. Funding Information: 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, and by the DESI Member Institutions: Aix-Marseille University; Argonne National Laboratory; Barcelona-Madrid Regional Participation Group; Brookhaven National Laboratory; Boston University; Brazil Regional Participation Group; Carnegie Mellon University; CEA-IRFU, Saclay; China Participation Group; Cornell University; Durham University; École Polytechnique Fédérale de Lausanne; Eidgenössische Technische Hochschule, Zürich; Fermi National Accelerator Laboratory; Granada-Madrid-Tenerife Regional Participation Group; Harvard University; Kansas State University; Korea Astronomy and Space Science Institute; Korea Institute for Advanced Study; Lawrence Berkeley National Laboratory; Laboratoire de Physique Nucléaire et de Hautes Energies; Ludwig Maximilians University; Max Planck Institute; Mexico Regional Participation Group; New York University; NSF's National Optical-Infrared Astronomy Research Laboratory; Ohio University; Perimeter Institute; Shanghai Jiao Tong University; Siena College; SLAC National Accelerator Laboratory; Southern Methodist University; Swinburne University; The Ohio State University; Universidad de los Andes; University of Arizona; University of Barcelona; University of California, Berkeley; University of California, Irvine; University of California, Santa Cruz; University College London; University of Florida; University of Michigan at Ann Arbor; University of Pennsylvania; University of Pittsburgh; University of Portsmouth; University of Queensland; University of Rochester; University of Toronto; University of Utah; University of Waterloo; University of Wyoming; University of Zurich; UK Regional Participation Group; and Yale University. Publisher Copyright: © 2022. The Author(s). Published by the American Astronomical Society.

PY - 2022/10/20

Y1 - 2022/10/20

N2 - 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, 32 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 01 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.

AB - 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, 32 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 01 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.

KW - astro-ph.IM

KW - astro-ph.CO

U2 - 10.3847/1538-3881/ac882b

DO - 10.3847/1538-3881/ac882b

M3 - Article

SN - 0004-6256

VL - 164

SP - 1

EP - 62

JO - Astronomical Journal

JF - Astronomical Journal

IS - 5

M1 - 207

ER -

Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument

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