Related papers: Time-dependent Corotation Resonance in Barred Gala…
The inner parts of many spiral galaxies are dominated by bars. These are strong non-axisymmetric features which significantly affect orbits of stars and dark matter particles. One of the main effects is the dynamical resonances between…
The dynamics of the inner disk of many galaxies is dominated by bars. As a result, resonances between the bar and the disk become an important factor. In order to detect resonances, we measure angular and radial frequencies of individual…
Bars may induce morphological features, such as rings, through their resonances. Previous studies suggested that the presence of 'dark-gaps', or regions of a galaxy where the difference between the surface brightness along the bar major…
We test the idea that bar pattern speeds decrease with time owing to angular momentum exchange with a dark matter halo. If this process actually occurs, then the locations of the corotation resonance and other resonances should generally…
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…
We provide the first quantitative evidence for the deceleration of the Galactic bar from local stellar kinematics in agreement with dynamical friction by a typical dark matter halo. The kinematic response of the stellar disk to a…
Based on a high quality $N$-body simulation of a double bar galaxy model, we investigate the evolution of the bar properties, including their size, strength and instantaneous pattern speed derived by using three distinct methods: the…
We study the distinction and quantification of chaotic and regular motion in a time-dependent Hamiltonian barred galaxy model. Recently, a strong correlation was found between the strength of the bar and the presence of chaotic motion in…
Galaxy modelling is greatly simplified by assuming the existence of a global system of angle-action coordinates. Unfortunately, global angle-action coordinates do not exist because some orbits become trapped by resonances, especially where…
Galaxy models have long predicted that galactic bars slow down by losing angular momentum to their postulated dark haloes. When the bar slows down, resonance sweeps radially outwards through the galactic disc while growing in volume,…
Dark gaps are commonly seen in early-to-intermediate type barred galaxies having inner and outer rings or related features. In this paper, the morphologies of 54 barred and oval ringed galaxies have been examined with the goal of…
Dark gaps, low surface brightness regions along the bar minor axis, are expected to form as a consequence of secular evolution in barred galaxies. Although several studies have proposed links between dark gap locations and dynamical…
To address questions about the physical nature and origin of spiral arms in galaxies, it is necessary to measure their dynamical properties, such as the angular speed, $\Omega_p$, or the corotation radius. Observations suggest that galaxies…
The interactions among objects in a mean motion resonance are important for the orbital evolution of satellites and rings, especially Saturn's ring arcs and associated moons. In this work, we examine interactions among massive bodies in the…
In the presence of a strong $m=2$ component in a rotating galaxy, the phase space structure near corotation is shaped to a large extent by the {\it invariant manifolds} of the short period family of unstable periodic orbits terminating at…
A high-resolution N-body simulation suggests that stellar streams in the discs of barred galaxies are common and strongly time-dependent. The velocity distribution of stars in the Solar neighbourhood betray many such streams, including a…
The knowledge of the positions of the corotation resonance in spiral arms is a key way to estimate their pattern speed, which is a fundamental parameter determining the galaxy dynamics. Various methods for its estimation have been…
Density waves in galaxy disks have been proposed over the years, in a variety of specific models, to explain spiral arm structure and its relation to the mass distribution, notably in barred galaxies. An important parameter in dynamical…
We study how migration affects stars of a galaxy with a thin stellar disc and thicker stellar components. The simulated galaxy has a strong bar and lasting spiral arms. We find that the amplitude of the churning (change in angular momentum)…
Torus mapping yields constants of motion for stars trapped at a resonance. Each such constant of motion yields a system of contours in velocity space at the Sun and neighbouring points. If Jeans' theorem applied to resonantly trapped…