Abstract
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 con-straints on S8 and Ωm from 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(DECaLS),which covers about 10000 deg2 with 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 Ωm=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 of γ1 and γ2 separately,and find that they are consistent with each other,but the constraints from the γ1 component are much weaker than that from γ2 It implies a much worse data quality of γ1,which is likely due to additional shear uncertainties caused by CCD electronics(according to the survey strategy of DECaLS).We also perform a pure 2D analysis,which gives S8=0.81+0.03-0.04 and Ωm=0.25+0.06-0.05.Our findings demonstrate the potential of the PDF-SYM method for precision cosmology.
基金项目
National Key Research and Development Program of China(2023YFA 1607800)
National Key Research and Development Program of China(2023YFA1607802)
National Natural Science Foundation of China(11621303)
National Natural Science Foundation of China(11890691)
National Natural Science Foundation of China(12073017)
science research grants from China Manned Space Project(CMS-CSST-2021-A01)
维普
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