No Arabic abstract
We perform a self-calibration of the richness-to-mass ($N$-$M$) relation of CAMIRA galaxy clusters with richness $Ngeq15$ at redshift $0.2leq z<1.1$ by modeling redshift-space two-point correlation functions. These correlation functions are $xi_{mathrm{cc}}$ of CAMIRA clusters, the auto-correlation function $xi_{mathrm{gg}}$ of the CMASS galaxies spectroscopically observed in the BOSS survey, and the cross-correlation function $xi_{mathrm{cg}}$ between these two samples. We focus on constraining the normalization $A_{mathrm{N}}$ of the $N$-$M$ relation in a forward-modeling approach, carefully accounting for the redshift-space distortion, the Finger-of-God effect, and the uncertainty in photometric redshifts of CAMIRA clusters. The modeling also takes into account the projection effect on the halo bias of CAMIRA clusters. The parameter constraints are shown to be unbiased according to validation tests using a large set of mock catalogs constructed from N-body simulations. At the pivotal mass $M_{500}=10^{14}h^{-1}M_{odot}$ and the pivotal redshift $z_{mathrm{piv}} = 0.6$, the resulting normalization $A_{mathrm{N}}$ is constrained as $13.8^{+5.8}_{-4.2}$, $13.2^{+3.4}_{-2.7}$, and $11.9^{+3.0}_{-1.9}$ by modeling $xi_{mathrm{cc}}$, $xi_{mathrm{cc}}+xi_{mathrm{cg}}$, and $xi_{mathrm{cc}} + xi_{mathrm{cg}} + xi_{mathrm{gg}}$, with average uncertainties at levels of $36%$, $23%$, and $21%$, respectively. We find that the resulting $A_{mathrm{N}}$ is statistically consistent with those independently obtained from weak-lensing magnification and from a joint analysis of shear and cluster abundance, with a preference for a lower value at a level of $lesssim1.9sigma$. This implies that the absolute mass scale of CAMIRA clusters inferred from clustering is mildly higher than those from the independent methods. [abridged]
We present a statistical weak-lensing magnification analysis on an optically selected sample of 3029 texttt{CAMIRA} galaxy clusters with richness $N>15$ at redshift $0.2leq z <1.1$ in the Subaru Hyper Suprime-Cam (HSC) survey. We use two distinct populations of color-selected, flux-limited background galaxies, namely the low-$z$ and high-$z$ samples at mean redshifts of $approx1.1$ and $approx1.4$, respectively, from which to measure the weak-lensing magnification signal by accounting for cluster contamination as well as masking effects. Our magnification bias measurements are found to be uncontaminated according to validation tests against the null-test samples for which the net magnification bias is expected to vanish. The magnification bias for the full texttt{CAMIRA} sample is detected at a significance level of $9.51sigma$, which is dominated by the high-$z$ background. We forward-model the observed magnification data to constrain the normalization of the richness-to-mass ($N$--$M$) relation for the texttt{CAMIRA} sample with informative priors on other parameters. The resulting scaling relation is $Npropto {M_{500}}^{0.92pm0.13} (1 + z)^{-0.48pm0.69}$, with a characteristic richness of $N=left(17.72pm2.60right)$ and intrinsic log-normal scatter of $0.15pm0.07$ at $M_{500} = 10^{14}h^{-1}M_{odot}$. With the derived $N$--$M$ relation, we provide magnification-calibrated mass estimates of individual texttt{CAMIRA} clusters, with the typical uncertainty of $approx39%$ and $approx32%$ at richness$approx20$ and $approx40$, respectively. We further compare our magnification-inferred $N$--$M$ relation with those from the shear-based results in the literature, finding good agreement.
We present the first results of a pilot X-ray study of 37 rich galaxy clusters at $0.1<z<1.1$ in the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) field. Diffuse X-ray emissions from these clusters were serendipitously detected in the XMM-Newton fields of view. We systematically analyze X-ray images of 37 clusters and emission spectra of a subsample of 17 clusters with high photon statistics by using the XMM-Newton archive data. The frequency distribution of the offset between the X-ray centroid or peak and the position of the brightest cluster galaxy was derived for the optical cluster sample. The fraction of relaxed clusters estimated from the X-ray peak offsets in 17 clusters is $29pm11(pm13)$%, which is smaller than that of the X-ray cluster samples such as HIFLUGCS. Since the optical cluster search is immune to the physical state of X-ray-emitting gas, it is likely to cover a larger range of the cluster morphology. We also derived the luminosity-temperature relation and found that the slope is marginally shallower than those of X-ray-selected samples and consistent with the self-similar model prediction of 2. Accordingly, our results show that the X-ray properties of the optical clusters are marginally different from those observed in the X-ray samples. The implication of the results and future prospects are briefly discussed.
We present weak-lensing measurements using the first-year data from the Hyper Suprime-Cam Strategic Survey Program on the Subaru telescope for eight galaxy clusters selected through their thermal Sunyaev-Zeldovich (SZ) signal measured at 148 GHz with the Atacama Cosmology Telescope Polarimeter experiment. The overlap between the two surveys in this work is 33.8 square degrees, before masking bright stars. The signal-to-noise ratio of individual cluster lensing measurements ranges from 2.2 to 8.7, with a total of 11.1 for the stacked cluster weak-lensing signal. We fit for an average weak-lensing mass distribution using three different profiles, a Navarro-Frenk-White profile, a dark-matter-only emulated profile, and a full cosmological hydrodynamic emulated profile. We interpret the differences among the masses inferred by these models as a systematic error of 10%, which is currently smaller than the statistical error. We obtain the ratio of the SZ-estimated mass to the lensing-estimated mass (the so-called hydrostatic mass bias $1-b$) of $0.74^{+0.13}_{-0.12}$, which is comparable to previous SZ-selected clusters from the Atacama Cosmology Telescope and from the {sl Planck} Satellite. We conclude with a discussion of the implications for cosmological parameters inferred from cluster abundances compared to cosmic microwave background primary anisotropy measurements.
We present the first weak-lensing mass calibration and X-ray scaling relations of galaxy clusters and groups selected in the $eROSITA$ Final Equatorial Depth Survey (eFEDS) observed by Spectrum Roentgen Gamma/$eROSITA$ over a contiguous footprint with an area of $approx140$ deg$^2$, using the three-year (S19A) weak-lensing data from the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. In this work, a sample of $434$ optically confirmed galaxy clusters (and groups) at redshift $0.01lesssim z lesssim1.3$ with a median of $0.35$ is studied, of which $313$ systems are uniformly covered by the HSC survey to enable the extraction of the weak-lensing shear observable. In a Bayesian population modelling, we perform a blind analysis for the weak-lensing mass calibration by simultaneously modelling the observed count rate $eta$ and the shear profile $g$ of individual clusters through the count rate-to-mass-and-redshift ($eta$--$M_{500}$--$z$) and weak-lensing mass-to-mass-and-redshift ($M_{mathrm{WL}}$--$M_{500}$--$z$) relations, respectively, while accounting for the bias in these observables using simulation-based calibrations. As a result, the count rate-inferred and lensing-calibrated cluster mass is obtained from the joint modelling of the scaling relations, as the ensemble mass spanning a range of $10^{13}h^{-1}M_{odot}lesssim M_{500}lesssim10^{15} h^{-1}M_{odot}$ with a median of $approx10^{14} h^{-1}M_{odot}$ for the eFEDS sample. With the mass calibration, we further model the X-ray observable-to-mass-and-redshift relations, including the rest-frame soft-band and bolometric luminosity ($L_{mathrm{X}}$ and $L_{mathrm{b}}$), the emission-weighted temperature $T_{mathrm{X}}$, the mass of intra-cluster medium $M_{mathrm{g}}$, and the mass proxy $Y_{mathrm{X}}$, which is the product of $T_{mathrm{X}}$ and $M_{mathrm{g}}$. (abridged)
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$sigma$ 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 $M_{rm WL,500c} = (4.15pm0.61)times10^{14},M_odot/h$. The ratio of the stacked Planck Sunyaev-Zeldovich (SZ) mass to the stacked WL mass is $ langle M_{rm SZ}rangle/langle M_{rm WL}rangle = 1-b = 0.80pm0.14$. 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 $Lambda$CDM cosmology.