标题： DESI DR2 参考模拟：Uchuu-BGS 和 LRG 的聚类结果 显示英文标题

标题： DESI DR2 reference mocks: clustering results from Uchuu-BGS and LRG

摘要： 本工作的目标是构建模拟星系目录，这些目录能够准确再现星系数密度、聚类统计量以及重子特性（如明亮红星系（LRGs）的恒星质量，以及明亮星系样本（BGS）在$r$波段的绝对星等）的红移演化，基于暗能量光谱仪（DESI）前三年的观测数据。 为了实现这一目标，我们将子晕丰度匹配（SHAM）技术应用于 Uchuu$N$体模拟，该模拟在体积为$8\,h^{-3}\,\mathrm{Gpc}^{3}$的区域内跟踪了 2.1 万亿个粒子的演化，假设为 Planck 基础$\Lambda$CDM 宇宙学模型。 通过 SHAM 方法，我们将 LRGs 和 BGS-BRIGHT（$r<19.5$）星系填充到 Uchuu 子晕中，直至红移$z=1.1$，为 LRGs 分配恒星质量，为 BGS 星系分配亮度（直至$M_{\rm r}\leq 20$）。 此外，我们分析了每个示踪器的聚类对恒星质量和光度的依赖性。 我们的结果表明，Uchuu BGS-BRIGHT 和 LRG 模拟准确再现了观测到的聚类红移演化，在$1<r<20\,h^{-1}\,\mathrm{Mpc}$及以下分离度上一致性优于 5%，在 10% 以内对于$0.1<r<1\,h^{-1}\,\mathrm{Mpc}$。 对于 Uchuu-LRG 模拟，我们成功捕捉了聚类的恒星质量依赖性，而对于 Uchuu-BGS 模拟，我们复制了各种体积限制子样本的聚类。 我们还发现，在 BGS-BRIGHT 星系的光度和 LRG 的恒星质量对大尺度偏差的依赖性方面，数据与模拟之间有良好的一致性。 总的来说，这些结果为 DESI 提供了强大的工具，用于生成剩余调查的高保真光锥，从而增强我们对星系-暗物质晕关系的理解。 显示英文摘要

摘要： 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 Uchuu $N$-body simulation, which follows the evolution of 2.1 trillion particles within a volume of $8\,h^{-3}\,\mathrm{Gpc}^{3}$, assuming a Planck base-$\Lambda$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 $M_{\rm r}\leq 20$). 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 $1<r<20\,h^{-1}\,\mathrm{Mpc}$ and below 10\% for $0.1<r<1\,h^{-1}\,\mathrm{Mpc}$. 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.