Related papers: Orbital and escape dynamics in barred galaxies - I…
We establish a dynamical mechanism to explain the origin of the asymmetry between the arms observed in some barred disk galaxies, where one of the two arms emanating from the bar ends is very well defined, while the second one displays a…
We use the Smaller ALignment Index (SALI) method of chaos detection, to study the global dynamics of conservative dynamical systems described by differential or difference equations. In particular, we consider the well--known 2 and…
High resolution N-body simulations using different codes and initial condition techniques reveal two different behaviours for the rotation frequency of transient spiral arms like structures. Whereas unbarred disks present spiral arms nearly…
A significant fraction of local galaxies exhibit stellar bars, non-axisymmetric structures composed of stars, gas, and dust. Identifying key differences between the properties of barred and unbarred galaxies can uncover clues about the…
We investigate the short-term dynamical evolution of stellar grand-design spiral arms in barred spiral galaxies using a three-dimensional (3D) $N$-body/hydrodynamic simulation. Similar to previous numerical simulations of unbarred,…
Recent observational constraints restrict the strict applicability of stellar dynamics in spirals to a few rotation periods. However, stellar dynamics concepts such as periodic orbits are invaluable for understanding the various dynamical…
We study the mechanisms and evolutionary phases of bar formation in n-body simulations of a stellar disc and dark matter halo system using harmonic basis function expansion analysis to characterize the dynamical mechanisms in bar evolution.…
In a previous paper (Voglis et al. 2006a, paper I) we demonstrated that, in a rotating galaxy with a strong bar, the unstable asymptotic manifolds of the short period family of unstable periodic orbits around the Lagrangian points L$_1$ or…
Using an N-body+SPH code we have performed numerical simulations to investigate the dynamical effects of an interaction between an initially barred galaxy and a small spherical companion. In the models described here the small companion…
We present a two-step method to simulate and study non-circular motions in strongly barred galaxies. The first step is to constrain the initial parameters using a Bayesian analysis of each galaxy's azimuthally averaged rotation curve, the…
Most galaxies have a warped shape when they are seen from an edge-on point of view. The reason for this curious form is not completely known so far and in this work we apply dynamical system tools to contribute to its explanation. Starting…
A multi-faceted approach is described to constrain the importance of bar-driven evolution in disk galaxies, particularly bulge formation. N-body simulations are used to construct stellar kinematic bar diagnostics for edge-on systems and to…
This paper describes a framework for studying galaxy morphology, particularly bar strength, in a quantitative manner, and presents applications of this approach that reveal observational evidence for secular evolution in bar morphology. The…
Many barred galaxies, including the Large Magellanic Cloud (LMC), display strong lopsidedness and off-centre bars. The dynamical connection between bar-disc misalignments, internal mass asymmetries, and arm morphology is not yet fully…
We use probability density functions (pdfs) of sums of orbit coordinates, over time intervals of the order of one Hubble time, to distinguish weakly from strongly chaotic orbits in a barred galaxy model. We find that, in the weakly chaotic…
Angular momentum redistribution within barred galaxies drives their dynamical evolution. Angular momentum is emitted mainly by near-resonant material in the bar region and absorbed by resonant material mainly in the outer disc and in the…
We study the shape and kinematics of simulated dwarf galaxy discs in the APOSTLE suite of $\Lambda$CDM cosmological hydrodynamical simulations. We find that a large fraction of these gas-rich, star-forming discs show weak bars in their…
We investigate the dynamical origin and kinematic signatures of spiral structure in an N-body simulation of an isolated barred galaxy, assessing whether invariant manifold theory provides a consistent dynamical framework to disentangle the…
We investigate the dynamical response of stellar orbits in a rotating barred galaxy potential to the perturbation by a nuclear gaseous ring. The change in 3D periodic orbit families is examined as the gas accumulates near the inner Lindblad…
A 3D dynamical model is used to study the motion in the central parts of an elliptical galaxy, hosting a massive and dense nucleus. Our aim is to investigate the regular or chaotic character of the motion, with emphasis in the different…