On the Theory of Formation of Lopsided Spiral Galaxies

Abstract

In this paper, the phenomenon of lopsidedness associated with the observed effect of displacement of the core of a spiral galaxy from its geometric center is explained by the gravitational instability of individual perturbation modes. The main ones are perturbation modes with radial wave numbers \(N=3\) and \(N=5\), where the azimuthal index is \(m=1\). Unlike other authors, we studied the lopside instability phenomenon against the background of a non-stationary model of a nonlinearly pulsating disk. The mechanisms and criteria for the origin of the phenomenon of displacement of the core in spiral galaxies are revealed. In addition, to determine the dependence of this effect on the geometry of the gravitating system, we also carried out an analysis of lopsided perturbation modes in the framework of a spherical nonstationary model.