Spatial orientations of galaxies in seven Abell clusters of BM type II

Abstract

As a concluding paper in this series, we present an analysis of the spatial orientations of galaxies in seven Abell clusters of BM type II and compare the results with previous works. Four BM type II clusters (A1767, A1809, A2554, A2721) show a similar preferred alignment: spin vectors of galaxies tend to lie in the local supercluster plane and the projections of the spin vector tend to be oriented perpendicular with respect to the Virgo cluster centre. A preferred alignment of galaxies in cluster A2554 is noticed in both the two- and three-dimensional analyses. In a comparison with previous work, we noticed a systematic change (with distance, radial velocity, morphology and magnitude) in the galaxy alignments from early-type (BM I) to late-type (BM III) clusters. Possible explanations of these systematic changes will be discussed.