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

We present results from a set of mock lightcones for the DESI One-Percent Survey, created from the U CHUU simulation. This 8 h −3 Gpc 3 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 U CHUU (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 U CHUU 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 U CHUU , 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.

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Publication Details

Journal
Astronomy and Astrophysics
Published
2025-05-05
DOI
https://doi.org/10.1051/0004-6361/202451022
Citations
4
Primary Topic
Geographic Information Systems Studies
Type
article
Field-Weighted Citation Impact
26.89
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article

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

D. Kirkby, Chi An Dong-Páez, Will J. Percival, R. Miquel et al.
4 citations
Astronomy and Astrophysics
Geographic Information Systems Studies
26.89
article

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

D. Kirkby, Chi An Dong-Páez, Will J. Percival, R. Miquel, A. G. Smith, Michael S. Schubnell, Graziano Rossi, Eva-Maria Mueller, Florian Beutler, J. Ereza, Gregory Tarlé, José Edgar Madriz Aguilar, M. Siudek, M. Landriau, D. Bianchi, Axel de la Macorra, B. A. Weaver, P. Norberg, Jundan Nie, David J. Brooks, Shaun Cole, Marc Manera, Sihan Yuan, J. Lasker, Eusebio Sanchez, Satya Gontcho A Gontcho, Shadab Alam, ChangHoon Hahn, K. Honscheid, K. Fanning, J. E. Forero-Romero, Steven P. Ahlen, F. Prada, Aaron Meisner, K. Dawson, Theodore S. Kisner, Biprateep Dey, Mehdi Rezaie, R. Kehoe, John Moustakas, Claire Poppett, Mustapha Ishak, Zhiming Zhou, M. S. Wang, M. Vargas-Magaña, R. Vaisakh, T. Claybaugh
article en
4 citations

Abstract

We present results from a set of mock lightcones for the DESI One-Percent Survey, created from the U CHUU simulation. This 8 h −3 Gpc 3 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 U CHUU (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 U CHUU 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 U CHUU , 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.

Astronomy and AstrophysicsVol. 698
Openalex Percentile: Top 1%
Geographic Information Systems Studies
26.89
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