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DESI z ≳ 5 Quasar Survey. I. A First Sample of 400 New Quasars at z ∼ 4.7–6.6

Yang, Jinyi; Fan, Xiaohui; Gupta, Ansh; Myers, Adam D.; Palanque-Delabrouille, Nathalie; Wang, Feige; Yèche, Christophe; Aguilar, Jessica Nicole; Ahlen, Steven; Alexander, David M.; Brooks, David; Dawson, Kyle; de la Macorra, Axel; Dey, Arjun; Dhungana, Govinda; Fanning, Kevin; Font-Ribera, Andreu; Gontcho, Satya; Guy, Julien; Honscheid, Klaus; Juneau, Stephanie; Kisner, Theodore; Kremin, Anthony; Le Guillou, Laurent; Levi, Michael; Magneville, Christophe; Martini, Paul; Meisner, Aaron; Miquel, Ramon; Moustakas, John; Nie, Jundan; Percival, Will; Poppett, Claire; Prada, Francisco; Schlafly, Edward; Tarlé, Gregory; Vargas Magana, Mariana; Weaver, Benjamin Alan; Wechsler, Risa; Zhou, Rongpu; Zhou, Zhimin; Zou, Hu

DESI z ≳ 5 Quasar Survey. I. A First Sample of 400 New Quasars at z ∼ 4.7–6.6 Thumbnail


Jinyi Yang

Xiaohui Fan

Ansh Gupta

Adam D. Myers

Nathalie Palanque-Delabrouille

Feige Wang

Christophe Yèche

Jessica Nicole Aguilar

Steven Ahlen

David Brooks

Kyle Dawson

Axel de la Macorra

Arjun Dey

Govinda Dhungana

Kevin Fanning

Andreu Font-Ribera

Satya Gontcho

Julien Guy

Klaus Honscheid

Stephanie Juneau

Theodore Kisner

Anthony Kremin

Laurent Le Guillou

Michael Levi

Christophe Magneville

Paul Martini

Aaron Meisner

Ramon Miquel

John Moustakas

Jundan Nie

Will Percival

Claire Poppett

Francisco Prada

Edward Schlafly

Gregory Tarlé

Mariana Vargas Magana

Benjamin Alan Weaver

Risa Wechsler

Rongpu Zhou

Zhimin Zhou

Hu Zou


We report the first results of a high-redshift (z ≳ 5) quasar survey using the Dark Energy Spectroscopic Instrument (DESI). As a DESI secondary target program, this survey is designed to carry out a systematic search and investigation of quasars at 4.8 < z < 6.8. The target selection is based on the DESI Legacy Imaging Surveys (the Legacy Surveys) DR9 photometry, combined with the Pan-STARRS1 data and J-band photometry from public surveys. A first quasar sample has been constructed from the DESI Survey Validation 3 (SV3) and first-year observations until 2022 May. This sample includes more than 400 new quasars at redshift 4.7 ≤ z < 6.6, down to 21.5 magnitude (AB) in the z band, discovered from 35% of the entire target sample. Remarkably, there are 220 new quasars identified at z ≥ 5, more than one-third of existing quasars previously published at this redshift. The observations so far result in an average success rate of 23% at z > 4.7. The current spectral data set has already allowed analysis of interesting individual objects (e.g., quasars with damped Lyα absorbers and broad absorption line features), and statistical analysis will follow the survey's completion. A set of science projects will be carried out leveraging this program, including quasar luminosity function, quasar clustering, intergalactic medium, quasar spectral properties, intervening absorbers, and properties of early supermassive black holes. Additionally, a sample of 38 new quasars at z ∼ 3.8–5.7 discovered from a pilot survey in the DESI SV1 is also published in this paper.


Yang, J., Fan, X., Gupta, A., Myers, A. D., Palanque-Delabrouille, N., Wang, F., …Zou, H. (2023). DESI z ≳ 5 Quasar Survey. I. A First Sample of 400 New Quasars at z ∼ 4.7–6.6. Astrophysical Journal Supplement, 269(1), Article 27.

Journal Article Type Article
Acceptance Date Aug 31, 2023
Online Publication Date Nov 6, 2023
Publication Date Nov 1, 2023
Deposit Date Feb 26, 2024
Publicly Available Date Feb 26, 2024
Journal The Astrophysical Journal Supplement Series
Print ISSN 0067-0049
Electronic ISSN 1538-4365
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 269
Issue 1
Article Number 27
Keywords Space and Planetary Science; Astronomy and Astrophysics
Public URL


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