Are external perturbations responsible for chaotic motion in galaxies?

Abstract

We study the nature of motion in a logarithmic galactic dynamical model, with an additional external perturbation. Two different cases are investigated. In the first case the external perturbation is fixed, while in the second case it is varying with the time. Numerical experiments suggest, that responsible for the chaotic phenomena is the external perturbation, combined with the dense nucleus. Linear relationships are found to exist, between the critical value of the angular momentum and the dynamical parameters of the galactic system that is, the strength of the external perturbation, the flattening parameter and the radius of the nucleus. Moreover, the extent of the chaotic regions in the phase plane, increases linearly as the strength of the external perturbation and the flattening parameter increases. On the contrary, we observe that the percentage covered by chaotic orbits in the phase plane, decreases linearly, as the scale length of the nucleus increases, becoming less dense. Theoretical arguments are used to support and explain the numerically obtained outcomes. A comparison of the present outcomes with earlier results is also presented.

Published in Chaos, Solitons & Fractals journal

References in corpus (10)

• The Magellanic Stream, High-Velocity Clouds and the Sculptor Group
• Magellanic Cloud Structure from Near-IR Surveys II: Star Count Maps and the Intrinsic Elongation of the LMC
• Formation and evolution of the Magellanic Clouds. I.Origin of structural, kinematical, and chemical properties of the Large Magellanic Cloud
• On The Formation of Disk Galaxies and Massive Central Objects
• Production of Milky Way structure by the Magellanic Clouds
• A new dynamical model for the study of galactic structure
• Chaos and the Shapes of Elliptical Galaxies
• High-resolution N-body Simulations of Galactic Cannibalism: The Magellanic Stream
• The evolution of chaos in active galaxy models with an oblate or a prolate dark halo component
• Global Dynamics in Galactic Triaxial Systems I

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• Chaotic orbital dynamics of pulsating stars around black holes surrounded by dark matter halos
• Orbital dynamics in galactic potentials under mass transfer