CLASH: MASS DISTRIBUTION IN AND AROUND MACS J1206.2-0847 FROM A FULL CLUSTER LENSING ANALYSIS

Abstract

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 BVR c I c z imaging and our recent 16-band Hubble Space Telescope observations taken as part of the Cluster Lensing And Supernova survey with Hubble 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 northwest-southeast (NW-SE), aligned with the cluster and its brightest galaxy shapes, showing elongation with a 2:1 axis ratio in the plane of the sky. Our full-lensing mass profile exhibits a shallow profile slope d ln /d ln R -1 at cluster outskirts (R 1 Mpc h -1 ), whereas the mass distribution excluding the NW-SE excess regions steepens farther out, well described by the Navarro-Frenk-White form. Assuming a spherical halo, we obtain a virial mass M vir = (1.1 0.2 0.1) 10 15 M h -1 and a halo concentration c vir = 6.9 1.0 1.2 (c vir 5.7 when the central 50 kpc h -1 is excluded), which falls in the range 4 c 7 of average c(M, z) predictions for relaxed clusters from recent 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, they yield a cumulative gas mass fraction of 13.7 +4.5 -3.0 % at 0.7 Mpc h -1 (1.7 r 2500 ), a typical value observed for high-mass clusters.