Target Selection and Validation of DESI Quasars

Abstract The Dark Energy Spectroscopic Instrument (DESI) survey will measure large-scale structures using quasars as direct tracers of dark matter in the redshift range 0.9 < z < 2.1 and using Ly α forests in quasar spectra at z > 2.1. We present several methods to select candidate quasars for DESI, using input photometric imaging in three optical bands ( g , r , z ) from the DESI Legacy Imaging Surveys and two infrared bands (W1, W2) from the Wide-field Infrared Survey Explorer. These methods were extensively tested during the Survey Validation of DESI. In this paper, we report on the results obtained with the different methods and present the selection we optimized for the DESI main survey. The…

• NS
  National Science Foundation

  Awards: AST-0950945, 1911140, 0950945, AST-1911140
• UD
  U.S. Department of Energy

  Awards: DEAC0205CH11231, DE-SC0019022
• NA
  National Aeronautics and Space Administration
• GA
  Gordon and Betty Moore Foundation
• CI
  California Institute of Technology
• CA
  Chinese Academy of Sciences
• CN
  Consejo Nacional de Ciencia y Tecnología
• MD
  Ministerio de Ciencia e Innovación
• NT
  National Taiwan University

  Award: NTU-CC-111L894806
• CÀ
  Commissariat à l'Énergie Atomique et aux Énergies Alternatives
• OO
  Office of Science

  Awards: DE-SC0019022, DEAC0205CH11231
• JP
  Jet Propulsion Laboratory
• DO
  Division of Astronomical Sciences

  Award: AST-0950945
• HE
  High Energy Physics

  Award: DE-SC0019022
• LB
  Lawrence Berkeley National Laboratory