Clustering of emission line galaxies with IllustrisTNG ? I. Fundamental properties and halo occupation distribution
Clustering of emission line galaxies with IllustrisTNG ? I. Fundamental properties and halo occupation distribution
复制标题
使用 IllustrisTNG 进行发射线星系聚类？
DOI：
10.1093/mnras/stac3582
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发表时间：
2022
影响因子：
4.8
通讯作者：
Okumura Teppei
中科院分区：
文献类型：
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作者：
Osato Ken;Okumura Teppei
即将到来的光谱红移巡天使用发射线星系（ELG）来追踪更深宇宙中更大面积覆盖的三维物质分布。由于承载ELG的晕是年轻的，并沿着沿着的结构向更大质量的晕下沉，与广泛采用的发光红色星系样本相反，ELG特有的动力学应被考虑到在非线性尺度上改进理论模型。在本文中，我们仔细研究的晕占领分布（HOD）和集群的ELGs的性质，利用IllustrisTNG星系形成流体动力学模拟。利用星布居合成技术结合光电离模型，计算了模拟星系的谱线强度，并构造了模拟的H α和[Oii] ELG星表.谱线光度函数和星星形成率与谱线强度的关系与观测估计符合得很好。接下来，我们测量的HOD和证明，有一个独特的人口的中央HOD，这对应于低质量的下降晕。然后，我们执行HOD参数的统计推断从投影相关函数。我们的分析表明，推断的HOD显着偏离直接从模拟测量的HOD，虽然最佳拟合模型产生了很好的拟合投影相关函数。这意味着投影相关函数的信息内容不足以正确地约束HOD模型，因此，重要的是采用模拟ELG目录来校准HOD模型的函数形式，并添加关于HOD参数的先验信息来鲁棒地确定HOD。
Upcoming spectroscopic redshift surveys use emission line galaxies (ELGs) to trace the three-dimensional matter distributions with wider area coverage in the deeper Universe. Since the halos hosting ELGs are young and undergo infall towards more massive halos along filamentary structures, contrary to a widely employed luminous red galaxy sample, the dynamics specific to ELGs should be taken into account to refine the theoretical modelling at non-linear scales. In this paper, we scrutinize the halo occupation distribution (HOD) and clustering properties of ELGs by utilizing IllustrisTNG galaxy formation hydrodynamical simulations. Leveraging stellar population synthesis technique coupled with the photo-ionization model, we compute line intensities of simulated galaxies and construct mock H α and [Oii] ELG catalogues. The line luminosity functions and the relation between the star formation rate and line intensity are well consistent with observational estimates. Next, we measure the HOD and demonstrate that there is a distinct population for the central HOD, which corresponds to low-mass infalling halos. We then perform the statistical inference of HOD parameters from the projected correlation function. Our analysis indicates that the inferred HODs significantly deviate from the HOD measured directly from simulations although the best-fitting model yields a good fit to the projected correlation function. It implies that the information content of the projected correlation function is not adequate to constrain HOD models correctly and thus, it is important to employ mock ELG catalogues to calibrate the functional form of HOD models and add prior information on HOD parameters to robustly determine the HOD.