相关论文: Caught in the Act: Direct Detection of Galactic Ba…
The class `bulges' contains objects with very different formation and evolution paths and very different properties. I review two types of `bulges', the boxy/peanut bulges (B/Ps) and the discy bulges. The former are parts of bars seen…
Galactic bars are unstable to a vertical buckling instability which heats the disk and in some cases forms a boxy/peanut shaped bulge. We analyze the buckling instability as an application of classical Euler buckling followed by nonlinear…
Kn-band imaging of a sample of 30 edge-on spiral galaxies with a boxy or peanut-shaped (B/PS) bulge is discussed. Galaxies with a B/PS bulge tend to have a more complex morphology than galaxies with other bulge types, unsharp-masked images…
We use high resolution collisionless $N$-body simulations to study the secular evolution of disk galaxies and in particular the final properties of disks that suffer a bar and perhaps a bar-buckling instability. Although we find that bars…
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…
By using $N$-body and hydro simulations, we study the formation and evolution of bars in galaxies with significant gas content focusing on the phenomenon of the buckling instability. The galaxies are initially composed of a spherical dark…
The existence of a classical bulge in disk galaxies holds important clue to the assembly history of galaxies. Finding observational evidence of very low mass classical bulges particularly in barred galaxies including our Milky Way, is a…
Boxy/peanut bulges in disc galaxies have been associated to stellar bars. We analyse their properties in a large sample of $N$-body simulations, using different methods to measure their strength, shape and possible asymmetry, and then…
We explore trends in the morphology and line-of-sight (los) velocity of stellar populations in the inner regions of disc galaxies, using N-body simulations with both a thin (kinematically cold) and a thick (kinematically hot) disc which…
We show that direct detection and measurement of the vertically thickened parts of bars (so-called "boxy" or "peanut-shaped" bulges) is possible not only for edge-on galaxies but also for galaxies with moderate inclinations (i < 70 deg),…
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…
Boxy/peanut and X-shaped (BP/X) bulges are prominent features in edge-on disk galaxies and are believed to be vertically thickened bars. Despite their relevance in bar evolution, a statistically robust census of these structures in large…
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 have done a detailed study on the structural and kinematical properties of lenticular and early- and late-type spiral galaxies with bars, aiming to explore the formation and evolution processes of stellar bars in galaxies, and their…
We have observed 60 edge-on galaxies in the NIR in order to study the stellar distribution in galaxies with box/peanut-shaped bulges. The much smaller amount of dust extinction at these wavelengths allows us to identify in almost all target…
Recent data from the VVV survey have strengthened evidence for a structural change in the Galactic bulge inwards of |l|<=4 deg. Here we show with an N-body barred galaxy simulation that a boxy bulge formed through the bar and buckling…
We use stellar dynamical bulge/disk/halo simulations to study whether barlenses (lens-like structures embedded in the narrow bar component) are just the face-on counterparts of Boxy/Peanut/X-shapes (B/P/X) seen in edge-on bars, or if some…
Boxy/peanut bulges in disk galaxies have been associated to stellar bars. In this talk, we discuss the different properties of such bulges and their relation with the corresponding bar, using a very large sample of a few hundred numerical…
Galactic bars induce characteristic motions deviating from pure circular rotation, known as non-circular motions. As bars are non-axisymmetric structures, stronger bars are expected to show stronger non-circular motions. However, this has…
Simulations and observations of galactic bars suggest they do not commonly evolve into bulges, although it is possible that the earliest bars formed bulges long ago, when galaxies were smaller, denser, and had more gas. The most highly…