DESI DR2 reference mocks: clustering results fromUchuu-BGS and LRG
The aim of this work is to construct mock galaxy catalogues that accurately reproduce the redshift evolution of galaxy number density, clustering statistics, and baryonic properties, such as stellar mass for luminous red galaxies (LRGs) and absolute magnitude in the r-band for the bright galaxy samp...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:dnet:upcommonspor::013e3ce675699490dc3c786b3310755e |
| Acceso en línea: | https://hdl.handle.net/2117/461985 https://dx.doi.org/10.1088/1475-7516/2026/05/002 |
| Access Level: | acceso abierto |
| Palabra clave: | Cosmological simulations Galaxy clustering Galaxy evolution Power spectrum Àrees temàtiques de la UPC::Física::Astronomia i astrofísica |
| Sumario: | The aim of this work is to construct mock galaxy catalogues that accurately reproduce the redshift evolution of galaxy number density, clustering statistics, and baryonic properties, such as stellar mass for luminous red galaxies (LRGs) and absolute magnitude in the r-band for the bright galaxy sample (BGS), based on the first three years of observations from the Dark Energy Spectroscopic Instrument (DESI). To achieve this, we applied the subhalo abundance matching (SHAM) technique to the UchuuN-body simulation, which follows the evolution of 2.1 trillion particles within a volume of 8 h-3 Gpc3, assuming a Planck base-¿CDM cosmology. Using SHAM, we populated Uchuu subhalos with LRGs and BGS-BRIGHT (r < 19.5) galaxies up to redshift z = 1.1, assigning stellar masses to LRGs and luminosities to BGS galaxies (up to Mr = 20). Furthermore, we analyzed the clustering dependence on stellar mass and luminosity for each tracer. Our results show that the Uchuu BGS-BRIGHT and LRG mocks accurately reproduce the observed redshift evolution of clustering, with better than 5% agreement for separations of 1 < r < 20 h-1 Mpc and below a 10% for 0.1 < r < 1 h-1 Mpc. For the Uchuu-LRG mock, we successfully captured the stellar mass dependence of clustering, while for the Uchuu-BGS mock, we replicated the clustering for various volume-limited subsamples. We also find good agreement between the data and mocks in the dependence of large-scale bias on luminosity for BGS-BRIGHT galaxies and on stellar mass for LRGs. Altogether, these results equip DESI with robust tools for generating high-fidelity lightcones for the remainder of the survey, thereby enhancing our understanding of the galaxy-halo connection. |
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