ShaSS filamentary network connecting clusters

To achieve this, we have carried out a new redshift survey of galaxies across a 21 square degree region (17x17Mpc^2^) of the Shapley supercluster containing 11 rich clusters, all lying at z~0.048. This survey aims to provide full spectroscopic coverage of galaxies for the Shapley Supercluster Survey (ShaSS), a multiwavelength survey based on high-quality optical ugri and near-infrared K-band imaging acquired with the 2.6-m VST and 4.1-m VISTA telescopes.

Targets were selected from the VST images as having i<18.0 and WISE/W1<15.5mag, and the observations were carried out with the AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope. We present here redshift measurements for 4037 galaxies, of which 957 belong to the Shapley Supercluster. Including existing measurements, there are now reliable redshifts for 95 per cent of galaxies within the survey's magnitude limits over the 21deg^2^ region.