Speaker
Description
I will present cosmological constraints using the abundance of weak-lensing shear-selected galaxy clusters identified in the Hyper Suprime-Cam (HSC) Subaru Strategic Program. The clusters are selected on the mass maps constructed using the latest three-year (Y3) weak-lensing data covering an area of ≈ 500 deg2, yielding in a sample size of 129 clusters with a high signal-to-noise ratio 𝜈 of 𝜈 ≥ 4.7. Owing to the deep, wide-field, and uniform imaging of the HSC survey, this is by far the largest sample of shear-selected clusters, in which the selection solely depends on gravity and is free from any assumptions about the dynamical state. In Chiu+24, we obtain the fully marginalized constraint on $\hat{S}_8 \equiv \sigma_8 \left(\Omega_{m}/0.3\right)^{0.25} = 0.835^{+0.041}_{-0.044}$ (corresponding to a ~5% constraint) in a flat LCDM model, using the cluster abundance $N(\nu)$.
In the second part of my talk, I will present a blinded and updated analysis of the weak-lensing shear-selected cluster abundance in $N(\nu,z)$, in which the cluster redshift is determined by exploiting the HSC optical imaging in a data-driven approach (Chiu in prep.). By incorporating the information of cluster redshifts, we significantly improve the constraining power on $\Omega_{\mathrm{m}}$ by at least a factor of 3. I will discuss the methodology for weak-lensing shear-selected cluster cosmology in the ongoing and upcoming wide-field surveys.
| Other topic / keywords: | Gravitational lensing |
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