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Related papers: Galactic bar: normal mode of the stellar disk or s…

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I review the various mechanisms for creating bars in rotating stellar disks, and conclude that the swing-amplified feed-back loop, which produces rapidly tumbling bars, remains the most probable. The bar continues to evolve after its…

Astrophysics · Physics 2007-05-23 J A Sellwood

We study evolution of galactic bars using suite of very high-resolution zoom-in cosmological simulations of galaxies at z ~ 9-2. Our models were chosen to lie within similar mass DM halos, log(Mvir/Mo) ~ 11.65 +- 0.05, at z=6, 4, and 2, in…

Astrophysics of Galaxies · Physics 2022-08-03 Da Bi , Isaac Shlosman , Emilio Romano-Diaz

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

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…

Astrophysics · Physics 2009-11-10 Dimitri Alexei Gadotti

We show by numerical simulations that a purely stellar dynamical model composed of an exponential disc, a cuspy bulge, and an NFW halo with parameters relevant to the Milky Way Galaxy is subject to bar formation. Taking into account the…

Astrophysics of Galaxies · Physics 2016-08-17 Evgeny Polyachenko , Peter Berczik , Andreas Just

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

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…

Astrophysics of Galaxies · Physics 2018-07-23 Tommaso Zana , Massimo Dotti , Pedro R. Capelo , Silvia Bonoli , Francesco Haardt , Lucio Mayer , Daniele Spinoso

Recent progress in the understanding of the role of bars and gravitational instabilities in galaxy disks is reviewed. It has been proposed that bars can produce mass transfer towards the center, and progressively metamorphose late-type…

Astrophysics · Physics 2007-05-23 F. Combes

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

The arguments in favor of the unified formation mechanism for both slow (Lynden-Bell's) bars and common fast bars are given. This mechanism consists in a certain instability that is akin to the well-known radial orbit instability; it is…

Astrophysics · Physics 2007-05-23 E. V. Polyachenko , V. L. Polyachenko

From this vast subject, I will pick out and review three specific topics, namely the formation and evolution of bars, the formation of bulges, and the evolution during multiple major mergers. Bars form naturally in galactic discs. Their…

Astrophysics · Physics 2009-11-13 E. Athanassoula

We report idealized simulations that mimic the growth of galaxy disks embedded in responsive halos and bulges. The disks manifested an almost overwhelming tendency to form strong bars that we found very difficult to prevent. We found that…

Astrophysics of Galaxies · Physics 2017-10-11 Joel C. Berrier , J. A. Sellwood

Many barred galaxies, possibly including the Milky Way, have cusps in the centres. There is a widespread belief, however, that usual bar instability taking place in bulgeless galaxy models is impossible for the cuspy models, because of the…

Astrophysics of Galaxies · Physics 2017-02-07 E. V. Polyachenko , P. Berczik , A. Just

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

Stellar bars are important internal drivers of secular evolution in disk galaxies. Using a sample of nearby spiral galaxies with weak and strong bars, we explore the relationships between the star formation feature and stellar bars in…

Astrophysics of Galaxies · Physics 2015-06-22 Zhi-Min Zhou , Chen Cao , Hong Wu

Galactic bars drive the internal evolution of spiral galaxies, while their formation is tightly coupled to the properties of their host galaxy and dark matter halo. To explore what drives bar formation in the cosmological context and how…

Astrophysics of Galaxies · Physics 2025-03-05 Francesca Fragkoudi , Robert Grand , Rüdiger Pakmor , Facundo Gómez , Federico Marinacci , Volker Springel

While bars are commonly observed in disk galaxies, the precise conditions governing their formation remain incompletely understood. To investigate these conditions, we perform a suite of N-body simulations of bulgeless disk galaxies with…

Astrophysics of Galaxies · Physics 2025-09-10 Dajeong Jang , Woong-Tae Kim , Yun Hee Lee

This is the third of a series of papers presenting the first attempt to analyze the growth of the bar instability in a consistent cosmological scenario. In the previous two articles we explored the role of the cosmology on stellar disks,…

Astrophysics · Physics 2009-11-13 Anna Curir , Paola Mazzei , Giuseppe Murante

New observations in favour of a significant role of secular evolution are reviewed: central star formation boosted in pseudo-bulge barred galaxies, relations between bulge and disk, evidence for rejuvenated bulges. Numerical simulations…

Astrophysics · Physics 2015-06-24 F. Combes

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
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