Related papers: Dynamically possible pattern speeds of double bars
Galactic bars are found in the majority of disc galaxies. They rotate nearly rigidly with an angular frequency called pattern speed. Previous idealised simulations have shown that bar pattern speed decreases with time due to dynamical…
The dynamical stability and evolution of disc galaxies with different disc thickness as well as various fraction and concentration of stellar counter-rotation is investigated with self-consistent numerical simulations. In particular,…
Studies of the dynamics of globular clusters assume different values of bar parameters (mass, velocity, size) and analyse the results of orbit classifications over the range of the chosen values. It is also a usual thing that a spherical…
Galactic bars can form via the internal bar instability or external tidal perturbations by other galaxies. We systematically compare the properties of bars formed through the two mechanisms with a series of controlled $N$-body simulations…
We investigate the orbital dynamics of a \textit{barred-spiral} model when the system is rotating slowly and corotation is located beyond the end of the spiral arms. In the characteristic of the central family of periodic orbits we find a…
Although at least one quarter of early-type barred galaxies host secondary stellar bars embedded in their large-scale primary counterparts, the dynamics of such double barred galaxies are still not well understood. Recently we reported…
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 between the inner…
Inner regions of barred disk galaxies often include asymmetrical, small-scale central features, some of which are best described as secondary bars. Because orbital timescales in the galaxy center are short, secondary bars are likely to be…
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…
In the manifold theory of spiral structure in barred galaxies, the usual assumption is that the spirals rotate with the same pattern speed as the bar. Here we generalize the manifold theory under the assumption that the spirals rotate with…
Results from the modelling of bars in nearly 300 galaxies are used to test predictions from theoretical work on the evolution of bars. Correlations are found between bar ellipticity and boxiness, between bar strength and normalised size,…
We present surface photometry and stellar kinematics of NGC 2950, which is a nearby and undisturbed SB0 galaxy hosting two nested stellar bars. We use the Tremaine-Weinberg method to measure the pattern speed of the primary bar. This also…
A brief review is given of different methods used to determine the pattern speeds of the Galactic bar and spiral arms. The Galactic bar rotates rapidly, with corotation about halfway between the Galactic center and the Sun, and outer…
A substantial fraction of barred galaxies host additional nuclear bars which tumble with pattern speeds exceeding those of the large-scale (primary) stellar bars. We have investigated the mechanism of formation and dynamical decoupling in…
The arguments in favor of the unified formation mechanism for both slow (Lynden-Bell's) bars and common fast bars are given. This mechanism consists in a certain instability that is akin to the well-known radial orbit instability; it is…
Isolated barred galaxies evolve by redistributing their angular momentum, which, emitted by material in the inner disc at resonance with the bar, can be absorbed by resonant material in the outer disc, or in the halo. The amount of angular…
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 investigate the evolution of two bars formed in fully self-consistent hydrodynamic simulations of the formation of Milky Way-mass galaxies. One galaxy shows higher central mass concentration and has a longer and stronger bar than the…
We show that stable double-frequency orbits form the backbone of double bars, because they trap around themselves regular orbits, as stable closed periodic orbits do in single bars, and in both cases the trapped orbits occupy similar volume…
We present simulations of bar-unstable stellar discs in which the bars thicken into box/peanut shapes. Detailed analysis of the evolution of each model revealed three different mechanisms for thickening the bars. The first mechanism is the…