Figure 1: Dark matter distribution in the galaxy cluster MACSJ1206 reconstructed from combined strong and weak lensing analysis (Umetsu et al. 2012).

 

 

Figure 2: Ensemble averaged density profile of dark matter in CLASH galaxy clusters (Umetsu et al. 2016).

 

The results obtained here are generally favorable in terms of the standard explanation for dark matter as effectively cold and collisionless, with an excellent match between lensing data and CDM predictions for high-mass clusters. These studies represent a first step toward using cluster gravitational lensing to examine detailed predictions from cosmological simulations regarding the structure and shape of dark-matter halos. Such predictions can be unambiguously tested across a wide range of cluster masses and redshifts, with large statistical samples of clusters from ongoing and planned lensing surveys such as the Subar Hyper Suprime-Cam survey, the XXL survey, the eROSITA, WFIRST, and Euclid missions.

 

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