CLASH: Complete Lensing Analysis of the Largest Cosmic Lens MACS
  J0717.5+3745 and Surrounding Structures
  The galaxy cluster MACS J0717.5+3745 (z=0.55) is the largest known cosmic
lens, with complex internal structures seen in deep X-ray, Sunyaev-Zel'dovich
effect and dynamical observations. We perform a combined weak and strong
lensing analysis with wide-field BVRi'z' Subaru/Suprime-Cam observations and
16-band Hubble Space Telescope observations taken as part of the Cluster
Lensing And Supernova survey with Hubble (CLASH). We find consistent weak
distortion and magnification measurements of background galaxies, and combine
these signals to construct an optimally estimated radial mass profile of the
cluster and its surrounding large-scale structure out to 5 Mpc/h. We find
consistency between strong-lensing and weak-lensing in the region where these
independent data overlap, <500 kpc/h. The two-dimensional weak-lensing map
reveals a clear filamentary structure traced by distinct mass halos. We model
the lensing shear field with 9 halos, including the main cluster, corresponding
to mass peaks detected above 2.5\sigma_\kappa. The total mass of the cluster as
determined by the different methods is M_{vir}=(2.8\pm0.4) \times 10^15 M_sun.
Although this is the most massive cluster known at z>0.5, in terms of extreme
value statistics we conclude that the mass of MACS J0717.5+3745 by itself is
not in serious tension with LambdaCDM, representing only a ~2{\sigma} departure
above the maximum simulated halo mass at this redshift.
