# Preferred alignments of angular momentum vectors of galaxies in six dynamically unstable Abell clusters

## TL;DR

This study investigates the spatial orientations of galaxy angular momentum vectors in six dynamically unstable Abell clusters, finding no significant preferred alignments and supporting hierarchical galaxy formation models.

## Contribution

It introduces a method to convert 2D galaxy parameters into 3D rotation axes and compares observed distributions with isotropic simulations in unstable clusters.

## Key findings

- No preferred galaxy alignments in all six clusters.
- Clusters with substructures show local effects.
- Clusters exhibit higher velocity dispersion.

## Abstract

A spatial orientation of angular momentum vectors of galaxies in six dynamically unstable Abell clusters (S1171, S0001, A1035, A1373, A1474 and A4053) is studied. For this, two-dimensional observed parameters (e.g., positions, diameters, position angles) are converted into three-dimensional rotation axes of the galaxy using `position angle - inclination' method. The expected isotropic distribution curves for angular momentum vectors are obtained by performing random simulations. The observed and expected distributions are compared using several statistical tests. No preferred alignments of angular momentum vectors of galaxies are noticed in all six dynamically unstable clusters supporting hierarchy model of galaxy formation. These clusters have a larger value of velocity dispersion. However, local effects are noticed in the clusters that have substructures in the 1D-3D number density maps.