Implications of Galaxy Alignment for the Galaxy Formation Problem

Summary

The process of galaxy formation is one of the crucial problems of modern astronomy. Galactic alignments are important as a test of the various available scenarios for galaxy origin which predict different types of alignments. A method for investigating the galactic rotational axes is applied to two samples of galaxies chosen from the UGC, ESO and NGC catalogs for testing different models of galaxy formation. In the whole Supercluster the planes tend to be oriented perpendicularly to the Local Supercluster (LSC) plane. The effects strongly depend on the supergalactic coordinates. We compare the observed distribution of galactic rotation axes with theoretical models. Our results support the so-called “pancake” or “hedgehog” galaxy formation scenario and exclude the “turbulence” models. Moreover, we have some evidence on the importance of membership of clusters belonging to the LSC.

Introduction

Galactic alignments are a crucial problem for understanding the process of galaxy formation. Various scenarios of galaxy origin predict different types of galaxy alignments within superclusters. Analysis of LSC galaxies (Flin & Godlowski 1986; Godlowski 1991, 1992, 1993) has shown that the preferred orientation of the galactic plane is perpendicular to the LSC plane, and that the projection of the rotational axis on the LSC plane tends to be directed towards the Virgo Cluster center. The distributions of face-on and edge-on galaxies are different.