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Related papers: Time-dependent Pattern Speeds in Barred Galaxies

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We examine the observable properties of simulated barred galaxies including radial mass profiles, edge-on structure and kinematics, bar lengths and pattern speed evolution for detailed comparison to real systems. We have run several…

Astrophysics · Physics 2009-11-07 J. K. O'Neill , J. Dubinski

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…

Astrophysics of Galaxies · Physics 2024-12-09 Yirui Zheng , Juntai Shen

There is now clear evidence, from a variety of studies, that galactic bars contribute to and/or accelerate processes which quench galaxies. However, bars have a variety of strengths and pattern speeds, and previous work has suggested that…

Astrophysics of Galaxies · Physics 2026-04-22 Petra Mengistu , Karen L. Masters , Tobias Geron , R. J. Smethurst , Chris Lintott , B. D. Simmons

The dynamics of a barred galaxy depends on the angular velocity or pattern speed of its bar. Indeed, it is related to the location of corotation where gravitational and centrifugal forces cancel out in the rest frame of the bar. The only…

Astrophysics of Galaxies · Physics 2010-02-08 E. M. Corsini

We study the distinction and quantification of chaotic and regular motion in a time-dependent Hamiltonian barred galaxy model. Recently, a strong correlation was found between the strength of the bar and the presence of chaotic motion in…

Chaotic Dynamics · Physics 2015-03-20 T. Manos , T. Bountis , Ch. Skokos

We have used Spitzer images of a sample of 68 barred spiral galaxies in the local universe to make systematic measurements of bar length and bar strength. We combine these with precise determinations of the corotation radii associated with…

We run a suite of $N$-body simulations to investigate how classical bulges affect bar formation and properties under the internal formation mechanism. We incorporate bulges of varying mass and compactness into disk galaxy models and evolve…

Astrophysics of Galaxies · Physics 2026-03-13 Yirui Zheng , Juntai Shen , Bin-Hui Chen

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…

Astrophysics of Galaxies · Physics 2025-07-09 Ewa L. Lokas

We investigate the variation of bar strength with central velocity dispersion in a sample of barred spiral galaxies. The bar strength is characterized by $Q_g$, the maximal tangential perturbation associated with the bar, normalized by the…

Astrophysics · Physics 2014-11-18 M. Das , E. Laurikainen , H. Salo , R. Buta

This paper presents a new approach to studying galactic structures. They are considered as the low-frequency normal modes in a disc of orbits precessing at different angular speeds. Such a concept is an adequate alternative to the commonly…

Astrophysics · Physics 2009-11-10 E. V. Polyachenko

Isolated barred galaxies evolve by redistributing their internal angular momentum, which is emitted mainly at the inner disc resonances and absorbed mainly at the resonances in the outer disc and the halo. This causes the bar to grow…

Astrophysics · Physics 2007-05-23 E. Athanassoula

The dynamics of a barred galaxy depends on the pattern speed of its bar. The only direct method for measuring the pattern speed of a bar is the Tremaine-Weinberg technique. This method is best suited to the analysis of the distribution and…

Astrophysics · Physics 2009-11-13 E. M. Corsini

When integrals in the standard Tremaine-Weinberg method are evaluated for the case of a realistic model of a doubly barred galaxy, their modifications introduced by the second rotating pattern are in accord with what can be derived from a…

Astrophysics · Physics 2009-11-11 Witold Maciejewski

One of the challenges related to stellar bars is to accurately determine the length of the bar in a disc galaxy. In the literature, a wide variety of methods have been employed to measure the extent of a bar. However, a systematic study on…

Astrophysics of Galaxies · Physics 2024-03-19 Soumavo Ghosh , Paola Di Matteo

Bar structures can form internally due to the instability of their host galaxies or externally due to perturbations from other galaxies. We systematically quantify the growth timescales ($\tau_\mathrm{bar}$) of bars formed through these two…

Astrophysics of Galaxies · Physics 2025-07-01 Yirui Zheng , Juntai Shen , Xufen Wu , Bin-Hui Chen

Stellar bars and spiral arms co-exist and co-evolve in most disc galaxies in the local Universe. However, the physical nature of this interaction remains a matter of debate. In this work, we present a set of numerical simulations based on…

Astrophysics of Galaxies · Physics 2021-02-17 L. Garma-Oehmichen , L. Martinez-Medina , H. Hernández-Toledo , I. Puerari

When bars form within galaxy formation simulations in the standard cosmological context, dynamical friction with dark matter (DM) causes them to rotate rather slowly. However, almost all observed galactic bars are fast in terms of the ratio…

Astrophysics of Galaxies · Physics 2021-03-30 Mahmood Roshan , Indranil Banik , Neda Ghafourian , Ingo Thies , Benoit Famaey , Elena Asencio , Pavel Kroupa

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…

Chaotic Dynamics · Physics 2020-04-22 C. Efthymiopoulos , M. Harsoula , G. Contopoulos

This work examines the evolution of bar formation in disk galaxies over the last 6 giga-years by analyzing the barred galaxy fraction as a function of key structural parameters. A representative sample of local and distant field galaxies…

Astrophysics of Galaxies · Physics 2026-01-05 M. A. Chacón

The tumbling pattern of a bar is the main parameter characterising its dynamics. From numerical simulations, its evolution since bar formation is tightly linked to the dark halo in which the bar is formed through dynamical friction and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 I. Perez , J. A. L. Aguerri , J. Mendez-Abreu