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We present a comprehensive analysis of strong-lensing, weak-lensing shear and magnification data for a sample of 16 X-ray-regular and 4 high-magnification galaxy clusters selected from the CLASH survey. Our analysis combines constraints from 16-band HST observations and wide-field multi-color imaging taken primarily with Subaru/Suprime-Cam. We reconstruct surface mass density profiles of individual clusters from a joint analysis of the full lensing constraints, and determine masses and concentrations for all clusters. We find internal consistency of the ensemble mass calibration to be $le 5% pm 6%$ by comparison with the CLASH weak-lensing-only measurements of Umetsu et al. For the X-ray-selected subsample, we examine the concentration-mass relation and its intrinsic scatter using a Bayesian regression approach. Our model yields a mean concentration of $c|_{z=0.34} = 3.95 pm 0.35$ at $M_{200c} simeq 14times 10^{14}M_odot$ and an intrinsic scatter of $sigma(ln c_{200c}) = 0.13 pm 0.06$, in excellent agreement with LCDM predictions when the CLASH selection function based on X-ray morphological regularity and the projection effects are taken into account. We also derive an ensemble-averaged surface mass density profile for the X-ray-selected subsample by stacking their individual profiles. The stacked mass profile is well described by a family of density profiles predicted for cuspy dark-matter-dominated halos, namely, the NFW, Einasto, and DARKexp models, whereas the single power-law, cored isothermal and Burkert density profiles are disfavored by the data. We show that cuspy halo models that include the two-halo term provide improved agreement with the data. For the NFW halo model, we measure a mean concentration of $c_{200c} = 3.79^{+0.30}_{-0.28}$ at $M_{200c} = 14.1^{+1.0}_{-1.0}times 10^{14}M_odot$, demonstrating consistency between complementary analysis methods.
441 - Keiichi Umetsu 2015
We perform a 3D multi-probe analysis of the rich galaxy cluster A1689 by combining improved weak-lensing data from new BVRiz Subaru/Suprime-Cam observations with strong-lensing, X-ray, and Sunyaev-Zeldovich effect (SZE) data sets. We reconstruct the projected matter distribution from a joint weak-lensing analysis of 2D shear and azimuthally integrated magnification constraints, the combination of which allows us to break the mass-sheet degeneracy. The resulting mass distribution reveals elongation with axis ratio ~0.7 in projection. When assuming a spherical halo, our full weak-lensing analysis yields a projected concentration of $c_{200c}^{2D}=8.9pm 1.1$ ($c_{vir}^{2D}sim 11$), consistent with and improved from earlier weak-lensing work. We find excellent consistency between weak and strong lensing in the region of overlap. In a parametric triaxial framework, we constrain the intrinsic structure and geometry of the matter and gas distributions, by combining weak/strong lensing and X-ray/SZE data with minimal geometric assumptions. We show that the data favor a triaxial geometry with minor-major axis ratio 0.39+/-0.15 and major axis closely aligned with the line of sight (22+/-10 deg). We obtain $M_{200c}=(1.2pm 0.2)times 10^{15} M_{odot}/h$ and $c_{200c}=8.4pm 1.3$, which overlaps with the $>1sigma$ tail of the predicted distribution. The shape of the gas is rounder than the underlying matter but quite elongated with minor-major axis ratio 0.60+/-0.14. The gas mass fraction within 0.9Mpc is 10^{+3}_{-2}%. The thermal gas pressure contributes to ~60% of the equilibrium pressure, indicating a significant level of non-thermal pressure support. When compared to Plancks hydrostatic mass estimate, our lensing measurements yield a spherical mass ratio of $M_{Planck}/M_{GL}=0.70pm 0.15$ and $0.58pm 0.10$ with and without corrections for lensing projection effects, respectively.
We present a joint shear-and-magnification weak-lensing analysis of a sample of 16 X-ray-regular and 4 high-magnification galaxy clusters at 0.19<z<0.69 selected from the Cluster Lensing And Supernova survey with Hubble (CLASH). Our analysis uses wid e-field multi-color imaging, taken primarily with Suprime-Cam on the Subaru Telescope. From a stacked shear-only analysis of the X-ray-selected subsample, we detect the ensemble-averaged lensing signal with a total signal-to-noise ratio of ~25 in the radial range of 200 to 3500kpc/h. The stacked tangential-shear signal is well described by a family of standard density profiles predicted for dark-matter-dominated halos in gravitational equilibrium, namely the Navarro-Frenk-White (NFW), truncated variants of NFW, and Einasto models. For the NFW model, we measure a mean concentration of $c_{200c}=4.01^{+0.35}_{-0.32}$ at $M_{200c}=1.34^{+0.10}_{-0.09} 10^{15}M_{odot}$. We show this is in excellent agreement with Lambda cold-dark-matter (LCDM) predictions when the CLASH X-ray selection function and projection effects are taken into account. The best-fit Einasto shape parameter is $alpha_E=0.191^{+0.071}_{-0.068}$, which is consistent with the NFW-equivalent Einasto parameter of $sim 0.18$. We reconstruct projected mass density profiles of all CLASH clusters from a joint likelihood analysis of shear-and-magnification data, and measure cluster masses at several characteristic radii. We also derive an ensemble-averaged total projected mass profile of the X-ray-selected subsample by stacking their individual mass profiles. The stacked total mass profile, constrained by the shear+magnification data, is shown to be consistent with our shear-based halo-model predictions including the effects of surrounding large-scale structure as a two-halo term, establishing further consistency in the context of the LCDM model.
We derive an accurate mass distribution of the galaxy cluster MACS J1206.2-0847 (z=0.439) from a combined weak-lensing distortion, magnification, and strong-lensing analysis of wide-field Subaru BVRIz imaging and our recent 16-band Hubble Space Teles cope observations taken as part of the Cluster Lensing And Supernova survey with Hubble (CLASH) program. We find good agreement in the regions of overlap between several weak and strong lensing mass reconstructions using a wide variety of modeling methods, ensuring consistency. The Subaru data reveal the presence of a surrounding large scale structure with the major axis running approximately north-west south-east (NW-SE), aligned with the cluster and its brightest galaxy shapes, showing elongation with a sim 2:1 axis ratio in the plane of the sky. Our full-lensing mass profile exhibits a shallow profile slope dlnSigma/dlnRsim -1 at cluster outskirts (R>1Mpc/h), whereas the mass distribution excluding the NW-SE excess regions steepens further out, well described by the Navarro-Frenk-White form. Assuming a spherical halo, we obtain a virial mass M_{vir}=(1.1pm 0.2pm 0.1)times 10^{15} M_{sun}/h and a halo concentration c_{vir} = 6.9pm 1.0pm 1.2 (sim 5.7 when the central 50kpc/h is excluded), which falls in the range 4< <c> <7 of average c(M,z) predictions for relaxed clusters from recent Lambda cold dark matter simulations. Our full lensing results are found to be in agreement with X-ray mass measurements where the data overlap, and when combined with Chandra gas mass measurements, yield a cumulative gas mass fraction of 13.7^{+4.5}_{-3.0}% at 0.7Mpc/h (approx 1.7r_{2500}), a typical value observed for high mass clusters.
58 - Keiichi Umetsu 2011
We outline our methods for obtaining high precision mass profiles, combining independent weak-lensing distortion, magnification, and strong-lensing measurements. For massive clusters the strong and weak lensing regimes contribute equal logarithmic co verage of the radial profile. The utility of high-quality data is limited by the cosmic noise from large scale structure along the line of sight. This noise is overcome when stacking clusters, as too are the effects of cluster asphericity and substructure, permitting a stringent test of theoretical models. We derive a mean radial mass profile of four similar mass clusters of high-quality HST and Subaru images, in the range R=40kpc/h to 2800kpc/h, where the inner radial boundary is sufficiently large to avoid smoothing from miscentering effects. The stacked mass profile is detected at 58-sigma significance over the entire radial range, with the contribution from the cosmic noise included. We show that the projected mass profile has a continuously steepening gradient out to beyond the virial radius, in remarkably good agreement with the standard Navarro-Frenk-White form predicted for the family of CDM-dominated halos in gravitational equilibrium. The central slope is constrained to lie in the range, -dln{rho}/dln{r}=0.89^{+0.27}_{-0.39}. The mean concentration is c_{vir}=7.68^{+0.42}_{-0.40} (at a mean virial mass 1.54^{+0.11}_{-0.10}times 10^{15} M_{sun}/h), which is high for relaxed, high-mass clusters, but consistent with LCDM when a sizable projection bias estimated from N-body simulations is considered. This possible tension will be more definitively explored with new cluster surveys, such as CLASH, LoCuSS, Subaru HSC, and XXM-XXL, to construct the c-M relation over a wider mass range.
108 - Keiichi Umetsu 2010
Weak gravitational lensing of background galaxies is a unique, direct probe of the distribution of matter in clusters of galaxies. We review several important aspects of cluster weak gravitational lensing together with recent advances in weak lensing techniques for measuring cluster lensing profiles and constraining cluster structure parameters.
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