CoLoRe-2LPT：用于DESI宇宙学分析验证的莱曼α模拟星表
CoLoRe-2LPT: Lyman-$α$ mock catalogues for the validation of DESI cosmological analyses
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中文总结 AI 辅助
该研究开发了基于2LPT的CoLoRe-2LPT Lyα模拟星表，用于DESI宇宙学分析验证，其精度高、计算高效，可复现关键统计量并改进类星体成团性，为DESI分析提供了重要支撑。
中文摘要 AI 辅助
莱曼α（Lyα）森林已成为研究高红移（z > 2）宇宙大尺度结构的关键探针，为重子声学振荡（BAO）和物质全形（FS）成团提供了强有力的约束。作为即将开展的BAO和FS分析的核心要素，我们提出了新一代基于二阶拉格朗日微扰理论（2LPT）的快速宇宙学Lyα模拟星表。这些新模拟星表在准确捕捉小尺度成团以及恢复BAO峰的非线性展宽方面，相比此前的对数正态方法有显著改进；它们能够将Lyα统计量（包括Lyα偏倚、红移空间畸变β参数、平均透射流量和一维功率谱）复现至最新DESI测量值的10%以内。对应类星体（QSO）的成团性也较此前方法有所提升，通过高分辨率Abacus模拟校准，将观测到的QSO线性偏倚恢复至5%以内，并通过2LPT速度及添加“上帝之指”（Fingers-of-God）效应改进了红移空间畸变。此外，这些模拟星表还包含高柱密度系统和金属线，使我们能够探究这些天体物理污染物引发的效应和系统误差。这组新模拟星表对增强DESI DR2 Lyα全形宇宙学分析的建模与验证起到了关键作用，为模拟当前及下一代Lyα巡天、验证FS和BAO分析提供了物理动机明确且计算高效的工具。
英文摘要
The Lyman-$α$ (Ly$α$) forest has become a crucial probe for studying the large-scale structure of the universe at high redshift ($z > 2$), providing powerful constraints on Baryon Acoustic Oscillations (BAO) and the full-shape (FS) clustering of matter. As a key ingredient for upcoming BAO and FS analyses, we present a new generation of fast cosmological Ly$α$ mocks based on second-order Lagrangian perturbation theory (2LPT). These new mocks significantly improve upon previous log-normal approaches, both at accurately capturing small scale clustering and at recovering the non-linear broadening of the BAO peak. They are able to reproduce Ly$α$ statistics within $10\%$ of the latest DESI measurement; including the Ly$α$ bias and the redshift-space distortion $β$ parameter, mean transmitted flux, and 1D power spectrum. The corresponding quasar (QSO) clustering is also improved with respect to previous approaches, calibrated against high-resolution Abacus simulations, recovering the observational QSO linear bias to less than $5\%$ and improving redshift-space distortions via 2LPT velocities and the addition of Fingers-of-God effects. Furthermore, these mocks incorporate high column density systems and metal lines, allowing us to explore the effects and systematics induced by these astrophysical contaminants. This new set of mocks has been key for enhancing the modeling and validation of the DESI DR2 Ly$α$ full shape cosmological analysis. This work provides a physically motivated and computationally efficient tool for simulating current and next-generation Ly$α$ surveys and validating FS and BAO analysis.
