Multiwavelength study of X-ray Luminous Clusters in the Hyper
  Suprime-Cam Subaru Strategic Program S16A field
  We present a joint X-ray, optical and weak-lensing analysis for X-ray
luminous galaxy clusters selected from the MCXC (Meta-Catalog of X-Ray Detected
Clusters of Galaxies) cluster catalog in the Hyper Suprime-Cam Subaru Strategic
Program (HSC-SSP) survey field with S16A data, As a pilot study of our planned
series papers, we measure hydrostatic equilibrium (H.E.) masses using
XMM-Newton data for four clusters in the current coverage area out of a sample
of 22 MCXC clusters. We additionally analyze a non-MCXC cluster associated with
one MCXC cluster. We show that H.E. masses for the MCXC clusters are correlated
with cluster richness from the CAMIRA catalog (Oguri et al. 2017), while that
for the non-MCXC cluster deviates from the scaling relation. The mass
normalization of the relationship between the cluster richness and H.E. mass is
compatible with one inferred by matching CAMIRA cluster abundance with a
theoretical halo mass function. The mean gas mass fraction based on H.E. masses
for the MCXC clusters is $\langle f_{\rm gas} \rangle = 0.125\pm0.012$ at
spherical overdensity $\Delta=500$, which is $\sim80-90$ percent of the cosmic
mean baryon fraction, $\Omega_b/\Omega_m$, measured by cosmic microwave
background experiments. We find that the mean baryon fraction estimated from
X-ray and HSC-SSP optical data is comparable to $\Omega_b/\Omega_m$. A
weak-lensing shear catalog of background galaxies, combined with photometric
redshifts, is currently available only for three clusters in our sample.
Hydrostatic equilibrium masses roughly agree with weak-lensing masses, albeit
with large uncertainty. This study demonstrates that further multiwavelength
study for a large sample of clusters using X-ray, HSC-SSP optical and weak
lensing data will enable us to understand cluster physics and utilize
cluster-based cosmology.
