New structure in the Shapley supercluster

We present new radial velocities for 306 bright (R < 16) galaxies in a 77 d eg(2) region of the Shapley supercluster, measured with the FLAIR-II spectr ograph on the UK Schmidt Telescope. The galaxies we measured were uniformly distributed over the survey area, in contrast to previous samples which we re concentrated in several rich Abell clusters. Most of the galaxies (230) were members of the Shapley supercluster: they trace out two previously unk nown sheets of galaxies linking the Abell clusters of the supercluster. In a 44 deg2 area of the supercluster excluding the Abell dusters, these sheet s alone represent an overdensity of a factor of 2.0+/-0.2 compared to a uni form galaxy distribution. The supercluster is not flattened in the Declinat ion direction as has been suggested in previous papers. Within our survey a rea the new galaxies contribute an additional 50% to the known contents of the Shapley supercluster, with a corresponding increase in its contribution to the motion of the Local Group.