Quasi-2D weak lensing cosmological constraints using the PDF-SYM method  

作　　者：Zhenjie Liu Jun Zhang Hekun Li Zhi Shen Cong Liu 

机构地区：[1]Department of Astronomy,Shanghai Jiao Tong University,Shanghai 200240,China [2]Shanghai Key Laboratory for Particle Physics and Cosmology,Shanghai 200240,China [3]Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2024年第7期44-58,共15页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Key Research and Development Program of China(Grant Nos.2023YFA1607800,and 2023YFA1607802);the National Natural Science Foundation of China(Grant Nos.11621303,11890691,and 12073017);the science research grants from China Manned Space Project(Grant No.CMS-CSST-2021-A01)。

摘　　要：Cosmic shear statistics,such as the two-point correlation function(2PCF),can be evaluated with the PDF-SYM method instead of the traditional weighted-sum approach.It makes use of the full PDF information of the shear estimators,and does not require weightings on the shear estimators,which can in principle introduce additional systematic biases.This work presents our constraints on S8and?mfrom the shear-shear correlations using the PDF-SYM method.The data we use is from the z-band images of the Dark Energy Camera Legacy Survey(DECa LS),which covers about 10000 deg2with more than 100 million galaxies.The shear catalog is produced by the Fourier Quad method,and well tested on the real data itself with the field-distortion effect.Our main approach is called quasi-2D as we do use the photo-z information of each individual galaxy,but without dividing the galaxies into redshift bins.We mainly use galaxy pairs within the redshift interval between 0.2 and 1.3,and the angular range from 4.7 to 180 arcmin.Our analysis yields S8=0.762±0.026 and?m=0.234±0.075,with the baryon effects and the intrinsic alignments included.The results are robust against redshift uncertainties.We check the consistency of our results by deriving the cosmological constraints from auto-correlations ofγ1andγ2separately,and find that they are consistent with each other,but the constraints from theγ1component are much weaker than that fromγ2.It implies a much worse data quality ofγ1,which is likely due to additional shear uncertainties caused by CCD electronics(according to the survey strategy of DECa LS).We also perform a pure 2D analysis,which gives S8=0.81_(-0.04)^(+0.03)and?m=0.25_(-0.05)^(+0.06).Our findings demonstrate the potential of the PDF-SYM method for precision cosmology.

关 键 词：weak lensing shear-shear correlations cosmological parameters observations analysis 

分 类 号：P159[天文地球—天文学]