Investigation of galactic alignment in LSC galaxy clusters

Abstract

We investigate the galactic axes orientations within 18 selected clusters, sub-structures of the Local Supercluster. For every cluster we map the parameter \Delta_{11} (Flin & God{\l}owski 1986) describing the galactic axes alignment with respect to a cluster pole changing along the entire celestial sphere. The resulting maps are analyzed for correlations of its maxima with directions from the cluster centre to 1.) the derived `physical' cluster poles, 2.) the Local Supercluster centre, 3.) the Virgo A centre and 4.) the Earth, i.e. along the line of sight (LOS). The strong maxima - with one exception - exist only for non-spiral (NS) sub-samples, with the maximum well correlated with the LOS direction. For clusters with a clearly defined weak maximum the conclusion generally does not change. For the spiral (S) sub-samples the maps are usually at the random noise level. In these cases a weaker, but still existent correlation with the LOS is observed and no other evident correlations are noted. We conclude that the strong systematic effect, generated by the process of galactic axis de-projection from its optical image, is present in the catalogue data. With the use of a simple model for the systematic effect we are able to reproduce the main characteristic features of the maps for NS galaxies. We note, however, a few clusters showing significant differences with respect to this model.Comment: LaTeX (21 pages, 10 gif figures); MNRAS, accepte