Some properties of galaxy structures

TL;DR

This study investigates galaxy structure properties, including orientation and ellipticity, revealing correlations with cluster richness and supercluster environment, and examines the Binggeli effect in different galaxy structures.

Contribution

It provides new insights into galaxy orientation anisotropy, ellipticity evolution, and the scale-dependent Binggeli effect across various galaxy structures.

Findings

Anisotropy increases with cluster richness.

Velocity dispersion decreases with Bautz-Morgan type.

Binggeli effect observed mainly in elongated structures.

Abstract

We analysed some properties of galaxies structures based on PF Catalogue of galaxy structures (Panko & Flin 2006) and Tully NBG Catalog (Tully 1988) At first, we analyzed the orientation of galaxies in the 247 optically selected rich Abell clusters, having in the area considered as cluster at least 100 members. The distribution of the position angles of the galaxy as well as two angles describing the spatial orientation of galaxy plane were tested for isotropy, applying three statistical tests. We found that anisotropy increases with the number of member galaxies, which means there exists the relation between anisotropy and cluster richness. We do not find connection of galaxy alignment and Bautz - Morgan morphological type of parent cluster. The statistically marginal relation between velocity dispersion and cluster richness was observed. However it was found that velocity dispersion decreases with Bautz - Morgan type at almost $3 \sigma$ level. Separately we analyzed ellipticities for 6188 low redshift ($z < 0.18$) poor and rich galaxy structures which have been examined along with their evolution. Finally we analysed the Binggeli effect. The orientation of galaxy groups in the Local Supercluster (LSC), is strongly correlated with the distribution of neighbouring groups in the scale till about 20 Mpc. During analyses of galaxy structures from PF catalogue the situation was quite different. The efect is observed only for more elongated structures ($e \le 0.3$). The range of the distance in which the effect was observed, was estimated as about $60 h^{-1} MPc$.