在 DESI-II 预期下通过 MillenniumTNG 检验莱曼α发射体
Examining Lyman-alpha Emitters through MillenniumTNG in anticipation of DESI-II
AI总结：
利用 MillenniumTNG 模拟高红移 LAE 星系，考察不同定义下的 HOD、线性/非线性聚集及组装偏置，为 DESI-II 等下一代观测设计提供依据。
摘要：
本研究的目标是对高红移恒星形成星系群体开展及时分析，这将为设计下一代实验及其河外目标提供信息。我们使用流体动力学模拟 MillenniumTNG（MTNG）对莱曼α发射（LAE）星系进行建模，以提取其聚集和占据统计等关键性质。我们通过恒星形成率（SFR）与莱曼α流量之间的经验关系来定义 LAE。我们还探讨了另外两种定义，发现对星系样本施加额外的最大恒星质量截断（用于近似高晕质量下低逃逸率的效应）会使该群体的线性偏置降低 5–10%。正如预期，我们发现 HOD 质量参数随数密度增加而迅速减小。此外，HOD 参数 σ 也随数密度减小，表明对于低光度天体，SFR–晕质量关系变得更紧密。令人惊讶的是，由参数 r0 估计的非线性聚集在固定数密度下保持固定，而线性偏置参数随红移变化为 b(z) ∝ (1 + z)，这表明我们的 LAE 样本相对稳定且长寿。最后，我们研究了 z = 2、3 时存在的星系组装偏置程度，发现 z = 2 时约为 ≲10%，而在 z = 3 时显著下降至 ≲5%。这表明在高 z 时组装偏置效应变得不那么重要，可能是由于累积的双晕相互作用（并合、回溅、剥离等）数量较少。尽管我们的研究基于单一的全物理模拟，但我们预期结果反映了宇宙中 LAE 的性质。我们证明，研究结果与以往使用观测和模拟所得结果高度一致。
英文摘要：
The goal of this study is to conduct a timely analysis of the high-redshift star-forming galaxy populations, which will be informative in designing next-generation experiments and their extragalactic targets. We use the hydrodynamical simulation MillenniumTNG (MTNG) to model Lyman-alpha Emitting (LAE) galaxies to extract key properties such as their clustering and occupation statistics. We define LAEs through an empirical relation between star formation rate (SFR) and Lyman-alpha flux. We also explore two other definitions, finding that imposing an additional cut on the maximum stellar mass of the galaxy sample, which approximates the effect of a low escape fraction at high halo mass, leads to a 5-10\% decrease of the linear bias of the population. As expected, we find that the HOD mass parameters rapidly decrease with increasing number density. Additionally, the HOD parameter $σ$ also decreases with number density, implying that the SFR-halo mass relationship becomes tighter for low-luminosity objects. Surprisingly, the non-linear clustering, estimated by the parameter $r_0$, is fixed at fixed number density, whereas the linear bias parameter varies with redshift as $b(z) \propto (1 + z)$, suggesting that our LAE samples are relatively stable and long-lived. Finally, we study the amount of galaxy assembly bias present at $z = 2, \ 3$ and find that while at $z = 2$ it is roughly $\lesssim$10\%, at $z = 3$ it decreases significantly to $\lesssim$5\%. This suggests that assembly bias effects become less important at high $z$ likely due to the lower number of cumulative two-halo interactions (mergers, splashback, stripping, etc.). While our study is based on a single full-physics simulation, we expect our results to reflect the properties of LAEs in the Universe. We demonstrate that our findings are in good agreement with previous results using both observations and simulations.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
