A spectroscopic survey of Abell 1703

Our analysis is based on unpublished spectroscopic data acquired at the Italian Telescopio Nazionale Galileo and data publicly available in the literature. We also use photometric data from the Sloan Digital Sky Survey.

We select 147 cluster members and compute the cluster redshift <z>~0.277 and the global line-of-sight velocity dispersion {sigma}_v_~1300km/s. We infer that Abell 1703 is a massive cluster: M_200_~1-2x10^15^M_{sun}_. The results of our study disagree with the picture of an unimodal, relaxed cluster as suggested by previous studies based on the gravitational lensing analysis and support the view of a perturbed dynamics proposed by recent works based on Chandra X-ray data.