arXiv subjects

Yen-Ting Lin

Publications and source records attributed to Yen-Ting Lin.

At least 73 records · Page 4Linked to original sources

arXiv2020

A 16 deg$^2$ survey of emission-line galaxies at z<1.6 from HSC-SSP PDR2 and CHORUS

We have conducted a comprehensive survey of emission-line galaxies at $z\lesssim1.6$ based on narrowband (NB) imaging data taken with Hyper Suprime-Cam (HSC) on the Subaru telescope. In this paper, we update the catalogs of H$α$, [OIII], and [OII] emission-line galaxies using the data from the second Public Data Release (PDR2) of Subaru Strategic Program (SSP) of HSC and Cosmic HydrOgen Reionization Unveiled with Subaru (CHORUS) survey along with the spectroscopic redshifts for 2,019 emission-line galaxies selected with the PDR1 data. The wider effective coverage of NB816 and NB921, 16.3 deg$^2$ and 16.9 deg$^2$ respectively, are available in the Deep and UltraDeep layers of HSC-SSP from the PDR2. The CHORUS survey provides us with data with additional three NBs (NB527, NB718, and NB973) in the COSMOS field in the UltraDeep layer (1.37 deg$^2$). The five NB datasets allow us to investigate the star-forming galaxies presenting emission-lines at 14 specific redshifts ranging from $z\sim1.6$ down to $z\sim0.05$. We revisit the distribution of large-scale structures and luminosity functions (LFs) for the emission-line galaxies with the large samples of 75,377 emission-line galaxies selected. The redshift revolution of LFs shows that the star formation rate densities (SFRDs) decreases monotonically from $z\sim1.6$, which is consistent with the cosmic SFRD ever known. Our samples of emission-line galaxies covering a sufficiently large survey volume are useful to investigate the evolution of star-forming galaxies since the cosmic noon in a wide range of environments including galaxy clusters, filaments, and voids.

astro-ph.GA↗

arXiv2020

The UV Luminosity Function of Protocluster Galaxies at $z\sim4$: the Bright-end Excess and the Enhanced Star Formation Rate Density

We report the rest-frame ultraviolet luminosity function of $g$-dropout galaxies in 177 protocluster candidates (PC UVLF) at $z\sim4$ selected in the Hyper Suprime-Cam Subaru Strategic Program. Comparing with the UVLF of field galaxies at the same redshift, we find that the PC UVLF shows a significant excess towards the bright-end. This excess can not be explained by the contribution of only active galactic nuclei, and we also find that this is more significant in higher dense regions. Assuming that all protocluster members are located on the star formation main sequence, the PC UVLF can be converted into a stellar mass function. Consequently, our protocluster members are inferred to have a 2.8 times more massive characteristic stellar mass than that of the field Lyman break galaxies at the same redshift. This study, for the first time, clearly shows that the enhancement in star formation or stellar mass in overdense regions can generally be seen as early as at $z\sim4$. We also estimate the star formation rate density (SFRD) in protocluster regions as $\simeq 6-20\%$ of the cosmic SFRD, based on the measured PC UVLF after correcting for the selection incompleteness in our protocluster sample. This high value suggests that protoclusters make a non-negligible contribution to the cosmic SFRD at $z\sim4$, as previously suggested by simulations. Our results suggest that protoclusters are essential components for the galaxy evolution at $z\sim4$.

astro-ph.GA↗

arXiv2020

Weak lensing clusters from HSC survey first-year data: Mitigating the dilution effect of foreground and cluster member galaxies

We present a weak lensing cluster search using Hyper Suprime-Cam Subaru Strategic Program (HSC survey) first-year data. We pay special attention to the dilution effect of cluster member and foreground galaxies on weak lensing signals from clusters of galaxies; we adopt the globally normalized weak lensing estimator which is least affected by cluster member galaxies, and we select source galaxies by using photometric redshift information to mitigate the effect of foreground galaxies. We produce six samples of source galaxies with different low-$z$ galaxy cuts, construct weak lensing mass maps for each of the source sample, and search for high peaks in the mass maps that cover an effective survey area of $\sim$120 deg$^2$. We combine six catalogs of high peaks into a sample of cluster candidates which contains 124 high peaks with signal-to-noise ratios greater than five. We cross-match the peak sample with the public optical cluster catalog constructed from the same HSC survey data to identify cluster counterparts of the peaks. We find that 107 out of 124 peaks have matched clusters within 5 arcmin from peak positions. Among them, we define a sub-sample of 64 secure clusters that we use to examine dilution effects on our weak lensing cluster search. We find that source samples with the low-$z$ galaxy cuts mitigate the dilution effect on weak lensing signals of high-$z$ clusters ($z > 0.3$), and thus combining multiple peak catalogs from different source samples improves the efficiency of weak lensing cluster searches.

astro-ph.CO↗

arXiv2020

SCUBA-2 Ultra Deep Imaging EAO Survey (STUDIES) IV: Spatial clustering and halo masses of 450-$μ$m-selected sub-millimeter galaxies

We analyze an extremely deep 450-$μ$m image ($1σ=0.56$\,mJy\,beam$^{-1}$) of a $\simeq 300$\,arcmin$^{2}$ area in the CANDELS/COSMOS field as part of the SCUBA-2 Ultra Deep Imaging EAO Survey (STUDIES). We select a robust (signal-to-noise ratio $\geqslant 4$) and flux-limited ($\geqslant 4$\,mJy) sample of 164 sub-millimeter galaxies (SMGs) at 450-$μ$m that have $K$-band counterparts in the COSMOS2015 catalog identified from radio or mid-infrared imaging. Utilizing this SMG sample and the 4705 $K$-band-selected non-SMGs that reside within the noise level $\leqslant 1$\,mJy\,beam$^{-1}$ region of the 450-$μ$m image as a training set, we develop a machine-learning classifier using $K$-band magnitude and color-color pairs based on the thirteen-band photometry available in this field. We apply the trained machine-learning classifier to the wider COSMOS field (1.6\,deg$^{2}$) using the same COSMOS2015 catalog and identify a sample of 6182 450-$μ$m SMG candidates with similar colors. The number density, radio and/or mid-infrared detection rates, redshift and stellar mass distributions, and the stacked 450-$μ$m fluxes of these SMG candidates, from the S2COSMOS observations of the wide field, agree with the measurements made in the much smaller CANDELS field, supporting the effectiveness of the classifier. Using this 450-$μ$m SMG candidate sample, we measure the two-point autocorrelation functions from $z=3$ down to $z=0.5$. We find that the 450-$μ$m SMG candidates reside in halos with masses of $\simeq (2.0\pm0.5) \times10^{13}\,h^{-1}\,\rm M_{\odot}$ across this redshift range. We do not find evidence of downsizing that has been suggested by other recent observational studies.

astro-ph.GA↗

arXiv2020

A Power-Efficient Binary-Weight Spiking Neural Network Architecture for Real-Time Object Classification

Neural network hardware is considered an essential part of future edge devices. In this paper, we propose a binary-weight spiking neural network (BW-SNN) hardware architecture for low-power real-time object classification on edge platforms. This design stores a full neural network on-chip, and hence requires no off-chip bandwidth. The proposed systolic array maximizes data reuse for a typical convolutional layer. A 5-layer convolutional BW-SNN hardware is implemented in 90nm CMOS. Compared with state-of-the-art designs, the area cost and energy per classification are reduced by 7$\times$ and 23$\times$, respectively, while also achieving a higher accuracy on the MNIST benchmark. This is also a pioneering SNN hardware architecture that supports advanced CNN architectures.

eess.SP↗

arXiv2020

Mass Bias of Weak Lensing Shear-selected Galaxy Cluster Samples

We estimate the bias on weak lensing mass measurements of shear-selected galaxy cluster samples. The mass bias is expected to be significant because constructions of cluster samples from peaks in weak lensing mass maps and measurements of cluster masses from their tangential shear profiles share the same noise. We quantify this mass bias from large sets of mock cluster samples with analytical density profiles and realistic large-scale structure noise from ray-tracing simulations. We find that, even for peaks with signal-to-noise ratio larger than $4.0$ in weak lensing mass maps constructed in a deep survey with a high source galaxy number density of $30~\mathrm{arcmin}^{-2}$, derived weak lensing masses for these shear-selected clusters are still biased high by $\sim55\%$ on average. Such a large bias mainly originates from up-scattered low mass objects, which is an inevitable consequence of selecting clusters with a noisy observable directly linked to the mass measurement. We also investigate the dependence of the mass bias on different physical and observational parameters, finding that the mass bias strongly correlates with cluster redshifts, true halo masses, and selection signal-to-noise thresholds, but having moderate dependence on observed weak lensing masses and survey depths. This bias, albeit considerable, can still be modeled accurately in statistical studies of shear-selected clusters as the intrinsic scatter around the mean bias is found to be reasonable in size. We demonstrate that such a bias can explain the deviation in X-ray properties previously found on a shear-selected cluster sample. Our result will be useful for turning large samples of shear-selected clusters available in future surveys into potential probes of cosmology and cluster astrophysics.

astro-ph.GA↗

arXiv2019

Second Data Release of the Hyper Suprime-Cam Subaru Strategic Program

This paper presents the second data release of the Hyper Suprime-Cam Subaru Strategic Program, a wide-field optical imaging survey on the 8.2 meter Subaru Telescope. The release includes data from 174 nights of observation through January 2018. The Wide layer data cover about 300 deg^2 in all five broadband filters (grizy) to the nominal survey exposure (10min in gr and 20min in izy). Partially observed areas are also included in the release; about 1100 deg^2 is observed in at least one filter and one exposure. The median seeing in the i-band is 0.6 arcsec, demonstrating the superb image quality of the survey. The Deep (26 deg^2) and UltraDeep (4 deg^2) data are jointly processed and the UltraDeep-COSMOS field reaches an unprecedented depth of i~28 at 5 sigma for point sources. In addition to the broad-bands, narrow-band data are also available in the Deep and UltraDeep fields. This release includes a major update to the processing pipeline, including improved sky subtraction, PSF modeling, object detection, and artifact rejection. The overall data quality has been improved, but this release is not without problems; there is a persistent deblender problem as well as new issues with masks around bright stars. The user is encouraged to review the issue list before utilizing the data for scientific explorations. All the image products as well as catalog products are available for download. The catalogs are also loaded to a database, which provides an easy interface for users to retrieve data for objects of interest. In addition to these main data products, detailed galaxy shape measurements withheld from the Public Data Release 1 (PDR1) are now available to the community. The shape catalog is drawn from the S16A internal release, which has a larger area than PDR1 (160 deg^2). All products are available at the data release site, https://hsc-release.mtk.nao.ac.jp/.

astro-ph.IM↗

arXiv2019

The whole picture of the large-scale structure of the CL1604 supercluster at z$\sim$0.9

We present the large-scale structure over more than 50 comoving Mpc scale at z $\sim$ 0.9 where the CL1604 supercluster, which is one of the largest structures ever known at high redshifts, is embedded. The wide-field deep imaging survey by the Subaru Strategic Program with Hyper Suprime-Cam reveals that the already-known CL1604 supercluster is a mere part of larger-scale structure extending to both the north and the south. We confirm that there are galaxy clusters at three slightly different redshifts in the northern and southern sides of the supercluster by determining the redshifts of 55 red-sequence galaxies and 82 star-forming galaxies in total by the follow-up spectroscopy with Subaru/FOCAS and Gemini-N/GMOS. This suggests that the structure ever known as the CL1604 supercluster is the tip of the iceberg. We investigate stellar population of the red-sequence galaxies using 4000 A break and Balmer H$δ$ absorption line. Almost all of the red-sequence galaxies brighter than 21.5 mag in $z$-band show an old stellar population with $\gtrsim2$ Gyr. The comparison of composite spectra of the red-sequence galaxies in the individual clusters show that the galaxies at a similar redshift have similar stellar population age, even if they are located $\sim$50 Mpc apart from each other. However, there could be a large variation in the star formation history. Therefore, it is likely that galaxies associated with the large-scale structure at 50 Mpc scale formed at almost the same time, have assembled into the denser regions, and then have evolved with different star formation history along the hierarchical growth of the cosmic web.

astro-ph.GA↗

arXiv2019

SILVERRUSH. VIII. Spectroscopic Identifications of Early Large Scale Structures with Protoclusters Over 200 Mpc at z~6-7: Strong Associations of Dusty Star-Forming Galaxies

We have obtained three-dimensional maps of the universe in $\sim200\times200\times80$ comoving Mpc$^3$ (cMpc$^3$) volumes each at $z=5.7$ and $6.6$ based on a spectroscopic sample of 179 galaxies that achieves $\gtrsim80$\% completeness down to the Ly$α$ luminosity of $\log(L_{\rm Lyα}/[\mathrm{erg\ s^{-1}}])=43.0$, based on our Keck and Gemini observations and the literature. The maps reveal filamentary large-scale structures and two remarkable overdensities made out of at least 44 and 12 galaxies at $z=5.692$ (z57OD) and $z=6.585$ (z66OD), respectively, making z66OD the most distant overdensity spectroscopically confirmed to date with $>10$ spectroscopically confirmed galaxies. We compare spatial distributions of submillimeter galaxies at $z\simeq 4-6$ with our $z=5.7$ galaxies forming the large-scale structures, and detect a $99.97\%$ signal of cross correlation, indicative of a clear coincidence of dusty star-forming galaxy and dust unobscured galaxy formation at this early epoch. The galaxies in z57OD and z66OD are actively forming stars with star formation rates (SFRs) $\gtrsim5$ times higher than the main sequence, and particularly the SFR density in z57OD is 10 times higher than the cosmic average at the redshift (a.k.a. the Madau-Lilly plot). Comparisons with numerical simulations suggest that z57OD and z66OD are protoclusters that are progenitors of the present-day clusters with halo masses of $\sim10^{14}\ \mathrm{M_\odot}$.

astro-ph.GA↗

arXiv2019

Quantum Degenerate Majorana Surface Zero Modes in Two-Dimensional Space

We investigate the topological properties of spin polarized fermionic polar molecules loaded in a multi-layer structure with the electric dipole moment polarized to the normal direction. When polar molecules are paired by attractive inter-layer interaction, unpaired Majorana fermions can be macroscopically generated in the top and bottom layers in dilute density regime. We show that the resulting topological state is effectively composed by a bundle of 1D Kitaev ladders labeled by in-plane momenta k and -k, and hence belongs to BDI class characterized by the winding number Z, protected by the time reversal symmetry. The Majorana surface modes exhibit a flatband at zero energy, fully gapped from Bogoliubov excitations in the bulk, and hence becomes an idea system to investigate the interaction effects on quantum degenerate Majorana fermions. We further show that additional interference fringes can be identified as a signature of such 2D Majorana surface modes in the time-of-flight experiment.

cond-mat.quant-gas↗

arXiv2018

The Massive and Distant Clusters of WISE Survey. I: Survey Overview and a Catalog of >2000 Galaxy Clusters at z~1

We present the Massive and Distant Clusters of WISE Survey (MaDCoWS), a search for galaxy clusters at 0.7 -30 degrees) and the remainder of the southern extragalactic sky at Dec<-30 degrees for which shallower optical data from SuperCOSMOS Sky Survey are available. In this paper we describe the search algorithm, characterize the sample, and present the first MaDCoWS data release -- catalogs of the 2433 highest amplitude detections in the WISE--Pan-STARRS region and the 250 highest amplitude detections in the WISE--SuperCOSMOS region. A total of 1723 of the detections from the WISE--Pan-STARRS sample have also been observed with the Spitzer Space Telescope, providing photometric redshifts and richnesses, and an additional 64 detections within the WISE--SuperCOSMOS region also have photometric redshifts and richnesses. Spectroscopic redshifts for 38 MaDCoWS clusters with IRAC photometry demonstrate that the photometric redshifts have an uncertainty of $σ_z/(1+z)\sim0.036$. Combining the richness measurements with Sunyaev-Zel'dovich observations of MaDCoWS clusters, we also present a preliminary mass-richness relation that can be used to infer the approximate mass distribution of the full sample. The estimated median mass for the WISE--Pan-STARRS catalog is $M_{500}=1.6^{+0.7}_{-0.8}\times10^{14} \mathrm{M}_\odot$, with the Sunyaev-Zel'dovich data confirming that we detect clusters with masses up to $M_{500}\sim5\times10^{14} \mathrm{M}_\odot$ $(M_{200}\sim10^{15} \mathrm{M}_\odot)$.

astro-ph.CO↗

arXiv2018

Scaling of the chiral magnetic effect in quantum diffusive Weyl semimetals

We investigate the effect of short-range spin-independent disorder on the chiral magnetic effect (CME) in Weyl semimetals. Based on a minimum two-band model, the disorder effect is examined in the quantum diffusion limit by including the Drude correction and the correction due to the Cooperon channel. It is shown that the Drude correction renormalizes the CME coefficient by a factor to a finite value that is independent of the system size. Furthemore, due to an additional momentum expansion involved in deriving the CME coefficient, the contribution of Cooperon to the CME coefficient is governed by the quartic momentum term. As a result, in contrast to the weak localization and weak anti-localization effects observed in the measurement of conductivity of Dirac fermions, we find that in the limit of zero magnetic field, the CME coefficients of finite systems manifest the same scaling of localization even in three dimension. Our results indicate that while the chiral magnetic current due to slowly oscillating magnetic fields can exist in clean systems, its observability will be limited by suppression due to short-range disorder in condensed matters.

cond-mat.mes-hall↗

arXiv2018

A Detection of the Environmental Dependence of the Sizes and Stellar Haloes of Massive Central Galaxies

We use ~100 square deg of deep (>28.5 mag arcsec$^{-2}$ in i-band), high-quality (median 0.6 arcsec seeing) imaging data from the Hyper Suprime-Cam (HSC) survey to reveal the halo mass dependence of the surface mass density profiles and outer stellar envelopes of massive galaxies. The i-band images from the HSC survey reach ~4 magnitudes deeper than Sloan Digital Sky Survey and enable us to directly trace stellar mass distributions to 100 kpc without requiring stacking. We conclusively show that, at fixed stellar mass, the stellar profiles of massive galaxies depend on the masses of their dark matter haloes. On average, massive central galaxies with $\log M_{\star, 100\ \mathrm{kpc}}>11.6$ in more massive haloes at 0.3 < z < 0.5 have shallower inner stellar mass density profiles (within ~10-20 kpc) and more prominent outer envelopes. These differences translate into a halo mass dependence of the mass-size relation. Central galaxies in haloes with $\log M_{\rm{Halo}}>14.0$ are ~20% larger in $R_{\mathrm{50}}$ at fixed stellar mass. Such dependence is also reflected in the relationship between the stellar mass within 10 and 100 kpc. Comparing to the mass--size relation, the $\log M_{\star, 100\ \rm{kpc}}$-$\log M_{\star, 10\ \rm{kpc}}$ relation avoids the ambiguity in the definition of size, and can be straightforwardly compared with simulations. Our results demonstrate that, with deep images from HSC, we can quantify the connection between halo mass and the outer stellar halo, which may provide new constraints on the formation and assembly of massive central galaxies.

astro-ph.GA↗

arXiv2018

An Analysis Framework for Understanding the Origin of Nuclear Activity in Low-Power Radio Galaxies

Using large samples containing nearly $2300$ active galaxies of low radio luminosity (1.4 GHz luminosity between $2\times 10^{23}$ and $3\times 10^{25}$ W/Hz, essentially low-excitation radio galaxies) at $z\lesssim 0.3$, we present a self-contained analysis of the dependence of the nuclear radio activity on both intrinsic and extrinsic properties of galaxies, with the goal of identifying the best predictors of the nuclear radio activity. While confirming the established result that stellar mass must play a key role in the triggering of radio activities, we point out that for central, most massive galaxies, the radio activity also shows a strong dependence on halo mass, which is unlikely due to enhanced interaction rates in denser regions in massive, cluster-scale halos. We thus further investigate the effects of various properties of the intracluster medium (ICM) in massive clusters on the radio activities, employing two standard statistical tools, Principle Component Analysis and Logistic Regression. It is found that ICM entropy, local cooling time, and pressure are the most effective in predicting the radio activity, pointing to the accretion of gas cooling out of a hot atmosphere to be the likely origin in triggering such activities in galaxies residing in massive dark matter halos. Our analysis framework enables us to logically discern the mechanisms responsible for the radio activity separately for central and satellite galaxies.

astro-ph.GA↗

arXiv2018

A large sample of shear selected clusters from the Hyper Suprime-Cam Subaru Strategic Program S16A wide field mass maps

We present the result of searching for clusters of galaxies based on weak gravitational lensing analysis of the $\sim 160$~deg$^2$ area surveyed by Hyper Suprime-Cam (HSC) as a Subaru Strategic Program. HSC is a new prime focus optical imager with a 1.5 diameter field of view on the 8.2-meter Subaru telescope. The superb median seeing on the HSC $i$-band images of $0.56$ arcsec allows the reconstruction of high angular resolution mass maps via weak lensing, which is crucial for the weak lensing cluster search. We identify 65 mass map peaks with signal-to-noise (SN) ratio larger than 4.7, and carefully examine their properties by cross-matching the clusters with optical and X-ray cluster catalogs. We find that all the 39 peaks with SN$>5.1$ have counterparts in the optical cluster catalogs, and only 2 out of the 65 peaks are probably false positives. The upper limits of X-ray luminosities from ROSAT All Sky Survey (RASS) imply the existence of an X-ray under-luminous cluster population. We show that the X-rays from the shear selected clusters can be statistically detected by stacking the RASS images. The inferred average X-ray luminosity is about half that of the X-ray selected clusters of the same mass. The radial profile of the dark matter distribution derived from the stacking analysis is well modeled by the Navarro-Frenk-White profile with a small concentration parameter value of $c_{500}\sim 2.5$, which suggests that the selection bias on the orientation or the internal structure for our shear selected cluster sample is not strong.

astro-ph.CO↗

arXiv2018

Planck Sunyaev-Zel'dovich Cluster Mass Calibration using Hyper Suprime-Cam Weak Lensing

Using $\sim$140 deg$^2$ Subaru Hyper Suprime-Cam (HSC) survey data, we stack the weak lensing (WL) signal around five Planck clusters found within the footprint. This yields a 15$σ$ detection of the mean Planck cluster mass density profile. The five Planck clusters span a relatively wide mass range, $M_{\rm WL,500c} = (2-30)\times10^{14}\,M_\odot/h$ with a mean mass of $M_{\rm WL,500c} = (4.15\pm0.61)\times10^{14}\,M_\odot/h$. The ratio of the stacked Planck Sunyaev-Zel'dovich (SZ) mass to the stacked WL mass is $ \langle M_{\rm SZ}\rangle/\langle M_{\rm WL}\rangle = 1-b = 0.80\pm0.14$. This mass bias is consistent with previous WL mass calibrations of Planck clusters within the errors. We discuss the implications of our findings for the calibration of SZ cluster counts and the much discussed tension between Planck SZ cluster counts and Planck $Λ$CDM cosmology.

astro-ph.CO↗

arXiv2017

First results on the cluster galaxy population from the Subaru Hyper Suprime-Cam survey. III. Brightest cluster galaxies, stellar mass distribution, and active galaxies

The unprecedented depth and area surveyed by the Subaru Strategic Program with the Hyper Suprime-Cam (HSC-SSP) have enabled us to construct and publish the largest distant cluster sample out to $z\sim 1$ to date. In this exploratory study of cluster galaxy evolution from $z=1$ to $z=0.3$, we investigate the stellar mass assembly history of brightest cluster galaxies (BCGs), evolution of stellar mass and luminosity distributions, stellar mass surface density profile, as well as the population of radio galaxies. Our analysis is the first high redshift application of the top N richest cluster selection, which is shown to allow us to trace the cluster galaxy evolution faithfully. Over the 230 deg$^2$ area of the current HSC-SSP footprint, selecting the top 100 clusters in each of the 4 redshift bins allows us to observe the buildup of galaxy population in descendants of clusters whose $z\approx 1$ mass is about $2\times 10^{14}\,M_\odot$. Our stellar mass is derived from a machine-learning algorithm, which is found to be unbiased and accurate with respect to the COSMOS data. We find very mild stellar mass growth in BCGs (about 35% between $z=1$ and 0.3), and no evidence for evolution in both the total stellar mass-cluster mass correlation and the shape of the stellar mass surface density profile. We also present the first measurement of the radio luminosity distribution in clusters out to $z\sim 1$, and show hints of changes in the dominant accretion mode powering the cluster radio galaxies at $z\sim 0.8$.

astro-ph.GA↗

arXiv2017

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 $Δ=500$, which is $\sim80-90$ percent of the cosmic mean baryon fraction, $Ω_b/Ω_m$, 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 $Ω_b/Ω_m$. 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.

astro-ph.CO↗