The DESI One-Percent Survey: Modelling the clustering and halo occupation of all four DESI tracers with UCHUU

¹ Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía, s/n, E-18008 Granada, Spain
² Institute for Computational Cosmology, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK
³ Department of Physics, Southern Methodist University, 3215 Daniel Avenue, Dallas, TX 75275, USA
⁴ Institute of Space Sciences, ICE-CSIC, Campus UAB, Carrer de Can Magrans s/n, 08913 Bellaterra, Barcelona, Spain
⁵ Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
⁶ Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
⁷ Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano, Via Celoria 16, I-20133 Milano, Italy
⁸ Department of Physics & Astronomy and Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT PACC), University of Pittsburgh, 3941 O’Hara Street, Pittsburgh, PA 15260, USA
⁹ Department of Physics and Astronomy, University of California, Irvine 92697, USA
¹⁰ Centre for Extragalactic Astronomy, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK
¹¹ Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
¹² Physics Dept., Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
¹³ Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, UK
¹⁴ Department of Physics and Astronomy, The University of Utah, 115 South 1400 East, Salt Lake City, UT 84112, USA
¹⁵ Instituto de Física, Universidad Nacional Autónoma de México, Cd. de México C.P. 04510, Mexico
¹⁶ Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Menlo Park, CA 94305, USA
¹⁷ SLAC National Accelerator Laboratory, Menlo Park, CA 94305, USA
¹⁸ Departamento de Física, Universidad de los Andes, Cra. 1 No. 18A-10, Edificio Ip, CP 111711 Bogotá, Colombia
¹⁹ Observatorio Astronómico, Universidad de los Andes, Cra. 1 No. 18A-10, Edificio H, CP 111711 Bogotá, Colombia
²⁰ Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
²¹ Center for Cosmology and AstroParticle Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, OH 43210, USA
²² Department of Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, OH 43210, USA
²³ The Ohio State University, Columbus, 43210 OH, USA
²⁴ Department of Physics, The University of Texas at Dallas, Richardson, TX 75080, USA
²⁵ Departament de Física, Serra Húnter, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain
²⁶ Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra Barcelona, Spain
²⁷ NSF NOIRLab, 950 N. Cherry Ave., Tucson, AZ 85719, USA
²⁸ Institució Catalana de Recerca i Estudis Avançats, Passeig de Lluís Companys, 23, 08010 Barcelona, Spain
²⁹ Department of Physics and Astronomy, Siena College, 515 Loudon Road, Loudonville, NY 12211, USA
³⁰ Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, UK
³¹ National Astronomical Observatories, Chinese Academy of Sciences, A20 Datun Rd., Chaoyang District, Beijing 100012, PR China
³² Department of Physics and Astronomy, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada
³³ Perimeter Institute for Theoretical Physics, 31 Caroline St. North, Waterloo, ON N2L 2Y5, Canada
³⁴ Waterloo Centre for Astrophysics, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada
³⁵ Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720, USA
³⁶ University of California, Berkeley, 110 Sproul Hall #5800 Berkeley, CA 94720, USA
³⁷ Department of Physics, Kansas State University, 116 Cardwell Hall, Manhattan, KS 66506, USA
³⁸ Department of Physics and Astronomy, Sejong University, Seoul 143-747, Korea
³⁹ CIEMAT, Avenida Complutense 40, E-28040 Madrid, Spain
⁴⁰ Department of Physics, University of Michigan, Ann Arbor, MI 48109, USA
⁴¹ University of Michigan, Ann Arbor, MI 48109, USA

^⋆ Corresponding author: f.prada@csic.es

Received: 7 June 2024
Accepted: 18 September 2024

Abstract

We present results from a set of mock lightcones for the DESI One-Percent Survey, created from the UCHUU simulation. This 8 h⁻³ Gpc³ N-body simulation comprises 2.1 trillion particles and provides high-resolution dark matter (sub)haloes in the framework of the Planck-based ΛCDM cosmology. Employing the subhalo abundance matching (SHAM) technique, we populated the UCHUU (sub)haloes with all four DESI tracers – Bright Galaxy Survey (BGS), luminous red galaxies (LRGs), emission line galaxies (ELGs), and quasars (QSOs) – to z = 2.1. Our method accounts for redshift evolution as well as the clustering dependence on luminosity and stellar mass. The two-point clustering statistics of the DESI One-Percent Survey generally agree with predictions from UCHUU across scales ranging from 0.3 h⁻¹ Mpc to 100 h⁻¹ Mpc for the BGS and across scales ranging from 5 h⁻¹ Mpc to 100 h⁻¹ Mpc for the other tracers. We observed some differences in clustering statistics that can be attributed to incompleteness of the massive end of the stellar mass function of LRGs, our use of a simplified galaxy-halo connection model for ELGs and QSOs, and cosmic variance. We find that at the high precision of UCHUU, the shape of the halo occupation distribution (HOD) of the BGS and LRG samples is smaller bias values, likely due to cosmic variance. The bias dependence on absolute magnitude, stellar mass, and redshift aligns with that of previous surveys. These results provide DESI with tools to generate high-fidelity lightcones for the remainder of the survey and enhance our understanding of the galaxy-halo connection.