Beyond the 3rd moment: a practical study of using lensing convergence CDFs for cosmology with DES Y3
Beyond the 3rd moment: a practical study of using lensing convergence CDFs for cosmology with DES Y3
复制标题
超越第三矩：使用透镜会聚 CDF 与 DES Y3 进行宇宙学的实际研究
DOI：
10.1093/mnras/stad3118
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发表时间：
2023
影响因子：
4.8
通讯作者：
Anbajagane D
中科院分区：
文献类型：
--
作者：
Anbajagane D
广角巡天探测聚集的标量场——比如星系数、透镜势等——它们对不同的宇宙学和天体物理过程很敏感。约束这些过程取决于汇总字段的统计信息。我们探索了累积分布函数（CDF）作为星系透镜收敛场的总结。通过一组n体光锥模拟，我们发现CDFs的约束能力略好于第二和第三矩，因为CDFs大致捕获了所有矩的信息。我们以暗能量调查（DES Y3）数据为例，研究了将CDFs应用于数据的实际方面，并计算了不同系统对CDFs的影响。点扩散函数和简化剪切近似的贡献是整个信号的贡献。源聚集效应和重子印记贡献了1 - 10%。强制缩减规模以限制参数约束中的系统驱动偏差，会显著降低这些约束，这种降低对于cdf和矩也是类似的。我们检测了在13σ处观测到的收敛场与形状噪声场之间的相关性。噪声场中的非高斯相关性必须精确建模，以使用cdf或其他对所有矩敏感的统计数据作为严格的宇宙学工具。
Widefield surveys probe clustered scalar fields – such as galaxy counts, lensing potential, etc. – which are sensitive to different cosmological and astrophysical processes. Constraining such processes depends on the statistics that summarize the field. We explore the cumulative distribution function (CDF) as a summary of the galaxy lensing convergence field. Using a suite ofN-body light-cone simulations, we show the CDFs’ constraining power is modestly better than the second and third moments, as CDFs approximately capture information from all moments. We study the practical aspects of applying CDFs to data, using the Dark Energy Survey (DES Y3) data as an example, and compute the impact of different systematics on the CDFs. The contributions from the point spread function and reduced shear approximation areof the total signal. Source clustering effects and baryon imprints contribute 1–10 per cent. Enforcing scale cuts to limit systematics-driven biases in parameter constraints degrade these constraints a noticeable amount, and this degradation is similar for the CDFs and the moments. We detect correlations between the observed convergence field and the shape noise field at 13σ. The non-Gaussian correlations in the noise field must be modelled accurately to use the CDFs, or other statistics sensitive to all moments, as a rigorous cosmology tool.