Filaments and pancakes in the IRAS 1.2 Jy redshift catalog

We explore the shapes of clusters and superclusters in the IRAS 1.2 Jy reds hift survey with three reconstructions spanning the range beta = 0.1, 0.5, and 1.0, where beta = Ohm(0.6)/b; b is the bias factor, and Ohm is the pres ent value of the dimensionless matter density. Comparing our results with G aussian randomized reconstructions of the IRAS catalog, we find structures having both planar and filamentary properties. For beta = 0.5 and 1.0, the largest structures in the survey have a distinct tendency to be filament-li ke, in general agreement with the results of N-body simulations.