论文标题
使用光度红移的DESI样发光红星系的聚类
The Clustering of DESI-like Luminous Red Galaxies Using Photometric Redshifts
论文作者
论文摘要
我们介绍了从传统调查成像数据集中选择的DESI样发光红色星系(LRG)样品的红移依赖性聚类的测量值,并使用Halo职业分布(HOD)框架符合聚类信号。这项研究中的光度LRG样本包含270万个物体,在$ 0.4 <z <z <z <0.9 $ 5655度$^2 $的范围内。我们已经使用Legacy调查DECAM和WISE光度法开发了新的光度红移(PHOTO-$ Z $)估计,并使用$σ_ {\ Mathrm {nmad}} = 0.02 $ lrgs的精度。我们使用新方法来计算投影相关函数,从而在结合红移不确定性的同时最大程度地提高信噪比。我们提出了一种新颖的算法,用于将不规则的调查几何形状分为相等的面积斑块,以重新采样。对于使用Multidark Halo目录拟合的五参数HOD模型,我们发现HOD参数几乎没有进化,除了最高的红移。推断的大规模结构偏置在很大程度上与随着时间的时间持续的聚类振幅一致。在附录中,我们使用将HOD方法应用于N体目录而产生的随机可能性估计值探索Markov Chain Monte Carlo拟合的局限性,并提出了一种在这种情况下找到最佳拟合参数的新技术。随附本文,我们发布了通过将本工作中使用的方法应用于完整的传统调查数据版本8数据集获得的光度调查(PRLS)目录的光度红移。该目录为物体提供了准确的光度红移,其$ z <21 $超过16,000度$^2 $的天空。
We present measurements of the redshift-dependent clustering of a DESI-like luminous red galaxy (LRG) sample selected from the Legacy Survey imaging dataset, and use the halo occupation distribution (HOD) framework to fit the clustering signal. The photometric LRG sample in this study contains 2.7 million objects over the redshift range of $0.4 < z < 0.9$ over 5655 deg$^2$. We have developed new photometric redshift (photo-$z$) estimates using the Legacy Survey DECam and WISE photometry, with $σ_{\mathrm{NMAD}} = 0.02$ precision for LRGs. We compute the projected correlation function using new methods that maximize signal-to-noise ratio while incorporating redshift uncertainties. We present a novel algorithm for dividing irregular survey geometries into equal-area patches for jackknife resampling. For a five-parameter HOD model fit using the MultiDark halo catalog, we find that there is little evolution in HOD parameters except at the highest redshifts. The inferred large-scale structure bias is largely consistent with constant clustering amplitude over time. In an appendix, we explore limitations of Markov chain Monte Carlo fitting using stochastic likelihood estimates resulting from applying HOD methods to N-body catalogs, and present a new technique for finding best-fit parameters in this situation. Accompanying this paper we have released the Photometric Redshifts for the Legacy Surveys (PRLS) catalog of photo-$z$'s obtained by applying the methods used in this work to the full Legacy Survey Data Release 8 dataset. This catalog provides accurate photometric redshifts for objects with $z < 21$ over more than 16,000 deg$^2$ of sky.