相关论文: Regular motions in double bars. I. Double-frequenc…

Bars in galaxies are mainly supported by particles trapped around closed periodic orbits. These orbits respond to the bar's forcing frequency only and lack free oscillations. We show that a similar situation takes place in double bars:…

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…

High-resolution observations of the inner regions of barred disk galaxies have revealed many asymmetrical, small-scale central features, some of which are best described as secondary bars. Because orbital time-scales in the galaxy center…

We show that non-chaotic multiply-periodic particle orbits can exist in a galaxy-like potential where a small fast-tumbling nuclear bar is nested inside a main bar which has a slower pattern speed. We introduce the concept of a loop: a…

The backbone of double bars is made out of double-frequency orbits, and loops, their maps, indicate the bars' extent, morphology and dynamics.

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…

Orbits in galaxy bars are generally complex, but simple closed loop orbits play an important role in our conceptual understanding of bars. Such orbits are found in some well-studied potentials, provide a simple model of the bar in…

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…

The first results of the observational program of the study of 2D-kinematics in double-barred galaxies are presented. We show that, for the main part of the sample, the inner bars do not affect the circumnuclear stellar kinematics.…

A large fraction of barred galaxies host secondary bars that are embedded in their large-scale primary counterparts. These are common also in gas poor early-type barred galaxies. The evolution of such double-barred galaxies is still not…

About one third of early-type barred galaxies host small-scale secondary bars. The formation and evolution of such double-barred galaxies remain far from being well understood. In order to understand the formation of such systems, we…

We describe the results of our spectroscopy for a sample of barred galaxies whose inner regions exhibit an isophotal twist commonly called a secondary bar. The line-of-sight velocity fields of the ionized gas and stars and the…

Although nearly one-third of barred galaxies host an inner, secondary bar, the formation and evolution of double barred galaxies remain unclear. We show here an example model of a galaxy, dominated by a live dark matter halo, in which…

We find that nuclear rings in barred galaxies can be subject to a new type of non-self-gravitational dynamical instability. The instability leads to the formation of gaseous molecular bars with pattern speeds which are substantially slower…

Many barred galaxies exhibit upturns (shoulders) in their bar major-axis density profile. Simulation studies have suggested that shoulders are supported by looped $x_1$ orbits, occur in growing bars, and can appear after bar-buckling. We…

It is widely believed that resonant orbits play an important role in formation and evolution of bars and large-scale spirals in galaxy discs. These resonant orbits have been studied in a number of specific potentials, often with an imposed…

Elongated bar-like features are ubiquitous in galaxies, occurring at the centers of approximately two-thirds of spiral disks in the nearby Universe. Due to gravitational interactions between the bar and the other components of galaxies, it…

Dynamics of regular clusters of many non-touching particles falling under gravity in a viscous fluid at low Reynolds number are analysed within the point-particle model. Evolution of two families of particle configurations is determined: 2…

Double-barred galaxies account for almost one third of all barred galaxies, suggesting that secondary stellar bars, which are embedded in large-scale primary bars, are long-lived structures. However, up to now it has been hard to…