Weak lensing cosmology with Subaru Hyper Suprime-Cam Year 3 data
Speaker: Sunao Sugiyama and Xiangchong Li
Abstract:
ΛCDM is the standard model of the Universe, which remarkably well explains a wide variety of observational results: accelerating universe via SNe, cosmic microwave background (CMB), and cosmological large-scale structure. Recently, several studies with data from stage-of-the-art galaxy surveys reported the so-called “S8 tension”, which states the discrepancy in the estimated cosmological-structure growth parameters, S8, from CMB observation vs. galaxy surveys, but they are still within the statistical uncertainty.
To test the ΛCDM model from the precise measurement of S8 parameter, we carried out the cosmological weak-lensing analyses using the wide-field imaging survey data by the Subaru Hyper Suprime-Cam (HSC). We constructed the galaxy-shape catalog from imaging data, the calibrated photo-z estimate for our galaxy samples, and the advanced residual PSF modeling. Using these intermediate data, we have performed four independent cosmological analyses in a blind fashion to avoid confirmation bias. We employed very conservative analysis choices against the potential systematics and validated the choices. After unblinding, we got consistent results among these four analyses, each of which gives a 5% constraint on S8 parameter and indicates 2~2.5 σ level S8 tension with Planck CMB result.