Gravitational Instability of Perturbations in a Background Nonlinear Nonstationary Model of a Disk-Like System. IV. Formation of two-ring structures in galaxies

TL;DR

This paper investigates the gravitational instability mechanisms leading to two-ring structures in galaxies by analyzing nonlinear, nonstationary disk models and deriving dispersion equations for structural vibration modes.

Contribution

It introduces a nonlinear, nonstationary model of galactic disks and derives dispersion equations to understand the formation of ring structures.

Findings

Derived nonstationary dispersion equations for galactic disk modes

Analyzed instability growth rates and their dependence on physical parameters

Identified criteria for two-ring structure formation in galaxies

Abstract

In order to identify the exact criteria for the formation of two-ring structures in galaxies, we studied the issue of gravitational instability of the corresponding structural vibration modes against the background of a composite disk model [1-3], which has an exact nonlinear law of nonstationarity. Nonstationary analogs of dispersion equations for the given structural vibration modes of the model are derived and the results of their analysis are obtained. A comparative analysis of the increments of instabilities of ring-like oscillation modes is carried out to determine the dependence of their characteristic times of manifestation on the main physical parameters of the model.