arXiv 2111.005012021-11astro-ph.COastro-ph.GA

LSST时代星系团的微扰理论模型：在傅立叶和位形空间中用亚百分比模拟星表测量的试验

Perturbation theory models for LSST-era galaxy clustering: tests with sub-percent mock catalog measurements in Fourier and configuration space

Samuel Goldstein, Shivam Pandey, Anže Slosar, Jonathan Blazek, Bhuvnesh Jain, The LSST Dark Energy Science Collaboration

发表信息：: Phys. Rev. D 105, 123518 (2022)
DOI：: 10.1103/PhysRevD.105.123518

阅读 PDF

arXiv 页面 ↗HTML 原文 ↗

摘要：

我们使用CosmoDC 2模拟的z=1.006快照来分析星系的聚类，CosmoDC 2模拟是一个高保真度的合成星系目录，旨在验证大型综合巡天望远镜（LSST）的分析方法。我们在傅立叶空间和位形空间中对一个星等有限的星系样本进行了星系自相关和星系-暗物质互相关的亚百分比测量。在这些水平的精度，测量的统计误差是可比的系统性的影响，目前在模拟和测量过程中，然而，使用混合PT模型，我们能够模拟非线性星系偏差与0.5%的精度高达尺度的$k_{\rm max}= 0.5 \ h/{\rm Mpc}$和$r_{\rm min}= 4 \ {\rm Mpc}/h$。虽然线性偏倚参数的测量精度为0.01%，但其他偏倚参数的确定具有相当弱的约束，有时具有双峰后验分布。我们比较了我们的基准模型与低维模型，其中高阶偏差参数固定在其共同进化值，并发现，让这些参数自由提供了显着的改进，我们的能力，以模拟小规模的信息。我们还比较了使用不同的星等带定义的星系样本的偏置参数，并发现包含相同数量的星系的样本之间的协议。最后，我们比较了傅立叶空间和位形空间的偏置参数，发现两种方法之间存在适度的张力。虽然我们的模型通常无法在我们测量的0.1%精度内拟合CosmoDC 2星系样本，但我们的结果表明，在此分析中使用的混合PT模型能够在即将到来的星系调查所需的百分比精度内对非线性星系偏差进行建模。

英文摘要：

We analyze the clustering of galaxies using the z=1.006 snapshot of the CosmoDC2 simulation, a high-fidelity synthetic galaxy catalog designed to validate analysis methods for the Large Synoptic Survey Telescope (LSST). We present sub-percent measurements of the galaxy auto-correlation and galaxy-dark matter cross correlations in Fourier space and configuration space for a magnitude-limited galaxy sample. At these levels of precision, the statistical errors of the measurement are comparable to the systematic effects present in the simulation and measurement procedure; nevertheless, using a hybrid-PT model, we are able to model non-linear galaxy bias with 0.5% precision up to scales of $k_{\rm max}= 0.5 \ h/{\rm Mpc}$ and $r_{\rm min}= 4 \ {\rm Mpc}/h$. While the linear bias parameter is measured with 0.01% precision, other bias parameters are determined with considerably weaker constraints and sometimes bimodal posterior distributions. We compare our fiducial model with lower dimensional models where the higher-order bias parameters are fixed at their co-evolution values and find that leaving these parameters free provides significant improvements in our ability to model small scale information. We also compare bias parameters for galaxy samples defined using different magnitude bands and find agreement between samples containing equal numbers of galaxies. Finally, we compare bias parameters between Fourier space and configuration space and find moderate tension between the two approaches. Although our model is often unable to fit the CosmoDC2 galaxy samples within the 0.1% precision of our measurements, our results suggest that the hybrid-PT model used in this analysis is capable of modeling non-linear galaxy bias within the percent level precision needed for upcoming galaxy surveys.

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。

摘要：

英文摘要：

相关论文