Related papers: Time-dependent Pattern Speeds in Barred Galaxies

We analyze how the orbital support of the inner bar in a double-barred galaxy (nested bars) depends on the angular velocity (i.e. pattern speed) of this bar. We study orbits in seven models of double bars using the method of invariant…

The method to study oscillating potentials of double bars, based on invariant loops, is introduced here in a new way, intended to be more intelligible. Using this method, I show how the orbital structure of a double-barred galaxy (nested…

Bars in spiral galaxies can weaken through gas inflow towards the center, and angular momentum transfer. Several bar episodes can follow one another in the life of the galaxy, if sufficient gas is accreted from the intergalactic medium to…

A significant fraction of barred spiral galaxies exhibits peanut/X-shaped structures in their central regions. Bars are known to rotate with a single pattern speed, and they eventually slow down over time due to the dynamical friction with…

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…

One of the main properties of galactic bars is their rotation (or pattern) speed, which is driven by both internal galactic properties, as well as external interactions. To assess the influence of these internal and external drivers on bar…

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 a study of the effect of bulge mass on the evolution of bar pattern speed in isolated disk galaxies using N-body simulations. Earlier studies have shown that disk stars at the inner resonances can transfer a significant amount of…

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…

We investigate the relations between the properties of bars and their host galaxies in a sample of 77 nearby barred galaxies, spanning a wide range of morphological types and luminosities, with 34 SB0-SBa and 43 SBab-SBc galaxies. The…

We investigate the orbital structure in a class of 3D models of barred galaxies. We consider different values of the pattern speed, of the strength of the bar and of the parameters of the central bulge of the galactic model. The morphology…

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…

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…

We have obtained two-dimensional velocity fields in the ionized gas of a set of 8 double-barred galaxies, at high spatial and spectral resolution, using their H$\alpha$ emission fields measured with a scanning Fabry-Perot spectrometer.…

We study the late-time evolution of the central regions of two Milky Way-like simulations of galaxies formed in a cosmological context, one hosting a fast bar and the other a slow one. We find that bar length, R_b, measurements fluctuate on…

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…

The pattern speed in one of the fundamental parameters that determines the structure of barred galaxies. This quantity is usually derived from indirect methods or by employing model assumptions. The number of bar pattern speeds derived…

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 study the dynamical interactions of mass systems in equilibrium under their own gravity that mutually exert and experience gravitational forces. The method we employ is to model the dynamical evolution of two isolated bars, hosted within…

Using N-body simulations, we study the properties of a bar induced in a dwarf galaxy as a result of tidal interaction with the Milky Way. The dwarf is initially composed of a disk embedded in a dark matter halo and we follow its evolution…