Related papers: Bar Formation, Evolution and Destruction
Spirals in galaxies have long been thought to be caused by gravitational instability in the stellar component of the disk, but discerning the precise mechanism had proved elusive. Tidal interactions, and perhaps bars, may provoke some…
The emergence of a large-scale stellar bar is one of the most striking features in disc galaxies. By means of state-of-the-art cosmological zoom-in simulations, we study the formation and evolution of bars in Milky Way-like galaxies in a…
This chapter reviews theoretical work on the stellar dynamics of galaxy disks. All the known collective global instabilities are identified, and their mechanisms described in terms of local wave mechanics. A detailed discussion of warps and…
We present a novel interpretation of the previously puzzling different behaviours of stellar populations of the Milky Way's bulge. We first show, by means of pure N-body simulations, that initially co-spatial stellar populations with…
N-body simulations have shown that a bar in a galaxy can be triggered by two processes: (1) by its own instabilities in the disk, or (2) by interactions with other galaxies. Both mechanisms have been widely studied. However, the literature…
In a galaxy merger, the stars tidally stripped from the satellite and accreted onto the host galaxy undergo phase mixing and form finely-grained structures in the phase space. However, these fragile structures may be destroyed in the…
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…
Although more than two-thirds of star-forming disk galaxies in the local universe are barred, some galaxies remain un-barred, occupying the upper half of the Hubble tuning fork diagram. Numerical simulations almost always produce bars…
The presence of spiral structure in isolated galaxies is a problem that has only been partially explained by theoretical models. Because the rate and pattern of star formation in the disk must depend only on mechanisms internal to the disk,…
It has been proposed that close interactions with satellite galaxies can significantly perturb the morphology of the main galaxy. However, the dynamics of an already formed bar following the interaction with the external environment has not…
Bars play a major role in driving the evolution of disk galaxies and in shaping their present properties. They cause angular momentum to be redistributed within the galaxy, emitted mainly from (near-)resonant material at the inner Lindblad…
I review the arguments for the importance of halo structure in driving galaxy evolution and coupling a galaxy to its environment. We begin with a general discussion of the key dynamics and examples of structure dominated by modes. We find…
The problem of how some disk galaxies avoid forming bars remains unsolved. Many galaxy models having reasonable properties continue to manifest vigorous instabilities that rapidly form strong bars and no widely-accepted idea has yet been…
Evolution of stellar bars in disk galaxies is accompanied by dynamical instabilities and secular changes. Following the vertical buckling instability, the bars are known to weaken dramatically and develop a pronounced boxy/peanut shape when…
We describe fully self-consistent N-body experiments of barred galaxies with massive halos. A rotating bar is braked through dynamical friction with the halo, which occurs on a short time scale when the central density of the halo is high.…
Non-axisymmetric modes like spirals and bars are the main driver of the evolution of disks, in transferring angular momentum, and allowing mass accretion. This evolution proceeds through self-regulation and feedback mechanisms, such as bar…
Many strong simulated galactic bars experience buckling instability, which manifests itself as a vertical distortion out of the disk plane, and later dissipates. Using a simulation of an isolated Milky Way-like galaxy, I demonstrate that…
We review our recent work on the formation and evolution of disks with in triaxial dark matter (DM) halos by means of numerical simulations, including star formation and feedback from stellar evolution. The growing disks are strongly in…
Many of the stars in the Galaxy were formed in binary systems. The widest of these can eventually become disrupted due to a combination of kicks from passing stars and the Galactic tidal field. If the Galactic disk were purely axisymmetric,…
Using $N$-body simulations we study the buckling instability in a galactic bar forming in a Milky Way-like galaxy. The galaxy is initially composed of an axisymmetric, exponential stellar disk embedded in a spherical dark matter halo. The…