Spectroscopy of strong lensing galaxy clusters

Our spectroscopic analysis yields redshifts for 52 gravitational arcs present in the core of our galaxy clusters, which correspond to 35 distinct background sources that are clearly distorted by the gravitational potential of these clusters. These lensed galaxies span a wide redshift range of 0.8<=z<=2.9, with a median redshift of z_s_=1.8+/-0.1.

We also measure reliable redshifts for 1004 cluster members, allowing us to obtain robust velocity dispersion measurements for 23 of these clusters, which we then use to determine their dynamical masses by using a simulation-based {sigma}_DM_-M_200_ scaling relation. The redshift and mass ranges covered by our SL sample are 0.22<=z<=1.01 and 5x10^13^M_200_/h_70_^-1^M_{sun}_<=1.9x10^15^, respectively. We analyze and quantify some possible effects that might bias our mass estimates, such as the presence of substructure, the region where cluster members are selected for spectroscopic follow-up, the final number of confirmed members, and line-of-sight effects.