Unveiling the Influence of Dark Matter in Axially Symmetric Galaxies

Abstract

We investigate the regular or chaotic nature of orbits of stars moving in the meridional plane (R,z) of an axially symmetric galactic model with a dense, massive spherical nucleus and a dark matter halo component. In particular, we study the influence of the fractional portion of the dark matter, by computing in each case the percentage of chaotic orbits, as well as the percentages of orbits of the main regular resonant families. In an attempt to distinguish between regular and chaotic motion, we use the Fast Lyapunov Indicator (FLI) method to extensive samples of orbits obtained by integrating numerically the equations of motion as well as the variational equations. Furthermore, a technique which is based mainly on the field of spectral dynamics that utilizes the Fourier transform of the time series of each coordinate is used for identifying the various families of regular orbits and also to recognize the secondary resonances that bifurcate from them. Two cases are studied in our work: (i) the case where we have a disk galaxy model (ii) the case where our model represents an elliptical galaxy. Comparison with early related work is also made.

Published in Publications of the Astronomical Society of Australia (PASA) journal. arXiv admin note: previous paper with related context: arXiv:1307.4205

References in corpus (9)

• High-Resolution Rotation Curves and Galaxy Mass Models from THINGS
• A systematic variation of the stellar initial mass function in early-type galaxies
• The Structure & Dynamics of Massive Early-type Galaxies: On Homology, Isothermality and Isotropy inside one Effective Radius
• The Black Hole Mass, Stellar M/L, and Dark Halo in M87
• Dynamical Centers and Non-Circular Motions in THINGS Galaxies: Implications for Dark Matter Halos
• The Globular Cluster System of M60 (NGC 4649). II. Kinematics of the Globular Cluster System
• A new dynamical model for the study of galactic structure
• Orbit classification in the meridional plane of a disk galaxy model with a spherical nucleus
• Mass Modelling with Minimum Kinematic Information

Cited by in corpus (8)

• Classifying orbits in the classical Henon-Heiles Hamiltonian system
• Classifying orbits in galaxy models with a prolate or an oblate dark matter halo component
• Dynamical Monte Carlo Simulations of 3-D Galactic Systems in Axisymmetric and Triaxial Potentials
• Revealing the influence of dark matter on the nature of motion and the families of orbits in axisymmetric galaxy models
• Determining the nature of orbits in disk galaxies with non spherical nuclei
• Orbit classification of low and high angular momentum stars
• Determining the type of orbits in the central regions of barred galaxies
• How does the mass transport in disk galaxy models influence the character of orbits?