Weak-lensing Shear-selected Galaxy Clusters from the Hyper Suprime-Cam Subaru Strategic Program: II. Cosmological Constraints from the Cluster Abundance

Kavli Affiliate: Masahiro Takada

| First 5 Authors: I-Non Chiu, Kai-Feng Chen, Masamune Oguri, Markus M. Rau, Hironao Miyatake

| Summary:

We present cosmological constraints using the abundance of weak-lensing
shear-selected galaxy clusters in the Hyper Suprime-Cam (HSC) Subaru Strategic
Program. The clusters are selected on the mass maps constructed using the
three-year (Y3) weak-lensing data with an area of $approx500~$deg$^2$,
resulting in a sample size of $129$ clusters with high signal-to-noise ratios
$nu$ of $nugeq4.7$. 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. Informed by the optical counterparts,
the shear-selected clusters span a redshift range of $zlesssim0.7$ with a
median of $zapprox0.3$. The lensing sources are securely selected at
$zgtrsim0.7$ with a median of $zapprox1.3$, leading to nearly zero cluster
member contamination. We carefully account for (1) the bias in the photometric
redshift of sources, (2) the bias and scatter in the weak-lensing mass using a
simulation-based calibration, and (3) the measurement uncertainty that is
directly estimated on the mass maps using an injection-based method developed
in a companion paper (Chen et al. submitted). In a blind analysis, the fully
marginalized posteriors of the cosmological parameters are obtained as
$Omega_{mathrm{m}} = 0.50^{+0.28}_{-0.24}$, $sigma_8 =
0.685^{+0.161}_{-0.088}$,
$hat{S}_{8}equivsigma_8left(Omega_{mathrm{m}}/0.3right)^{0.25} =
0.835^{+0.041}_{-0.044}$, and $sigma_8sqrt{Omega_{mathrm{m}}/0.3} =
0.993^{+0.084}_{-0.126}$ in a flat $Lambda$CDM model. We compare our
cosmological constraints with other studies, including those based on cluster
abundances, galaxy-galaxy lensing and clustering, and Cosmic Microwave
Background observed by $Planck$, and find good agreement at levels of
$lesssim2sigma$. [abridged]

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