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Related papers: Warp evidences in precessing galactic bar models

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The central theme of this thesis work is to explore the possibilities of spiral arm formations from instabilities formed inside the central region of disc galaxies. These instabilities originate from the central baryonic feedback and have…

Astrophysics of Galaxies · Physics 2024-10-10 Debasish Mondal

Recently, many orbital studies in barred galaxy potentials have revealed the existence of orbits which are not trapped around x1 tree orbits, but could be potentially appropriate building blocks for bars. These findings question the…

Astrophysics of Galaxies · Physics 2020-02-18 P. A. Patsis , E. Athanassoula

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

N-body simulations have shown that a bar in a galaxy can be triggered by two processes: (1) by its own instabilities in the disk, or (2) by interactions with other galaxies. Both mechanisms have been widely studied. However, the literature…

Astrophysics of Galaxies · Physics 2019-04-26 D. Valencia-Enríquez , I. Puerari , I. Rodrigues

We investigate the short-term dynamical evolution of stellar grand-design spiral arms in barred spiral galaxies using a three-dimensional (3D) $N$-body/hydrodynamic simulation. Similar to previous numerical simulations of unbarred,…

Astrophysics of Galaxies · Physics 2015-10-28 Junichi Baba

Evidence from a variety of sources points towards the existence of a bar in the central few kpc of the Galaxy. The measurements roughly agree on the direction of the bar major axis, but other parameters (axis ratio, size, pattern speed) are…

Astrophysics · Physics 2008-02-03 Konrad Kuijken

Stellar bars are elongated structures in disk galaxies that can torque and funnel gas inward, influencing galaxy evolution. While strong bars are known to induce rapid inflow, the impact of weaker bars remains less certain. We collected…

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 review results on the dynamics of warped gaseous discs. We consider tidal perturbation of a Keplerian disc by a companion star orbiting in a plane inclined to the disc. The perturbation induces the precession of the disc, and thus of any…

Astrophysics · Physics 2007-05-23 C. Terquem , J. Papaloizou , R. Nelson

Astrophysical discs are warped whenever a misalignment is present in the system, or when a flat disc is made unstable by external forces. The evolution of the shape and mass distribution of a warped disc is driven not only by external…

Solar and Stellar Astrophysics · Physics 2015-06-15 Gordon I. Ogilvie , Henrik N. Latter

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

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

Young stellar bars in disk galaxies experience a vertical buckling instability which terminates their growth and thickens them, resulting in a characteristic peanut/boxy shape when viewed edge on. Using N-body simulations of galactic disks…

Astrophysics · Physics 2009-11-10 Inma Martinez-Valpuesta , Isaac Shlosman

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…

Astrophysics · Physics 2007-05-23 Witold Maciejewski , Linda S. Sparke

We numerically investigate the orbital dynamics of a two-dimensional galactic model, emphasizing the influence of stable and unstable manifolds on the evolution of orbits. In our analysis we use evaluations of the system's Lagrangian…

Chaotic Dynamics · Physics 2025-05-19 Dylan Theron , Charalampos Skokos

Magellanic spiral galaxies are a class of one-armed systems that often exhibit an offset stellar bar, and are rarely found around massive spiral galaxies. Using a set of N-body and hydrodynamic simulations we consider a dwarf-dwarf galaxy…

Astrophysics of Galaxies · Physics 2016-08-25 Stephen A. Pardy , Elena D'Onghia , E. Athanassoula , Eric M. Wilcots , Kartik Sheth

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

With the prime aim of better probing and understanding the intimate link between star formation activity and the presence of bars, a representative sample of 32 non-interacting late-type galaxies with well-determined bar properties has been…

Astrophysics · Physics 2007-05-23 L. Martinet , D. Friedli

More than 10% of the barred galaxies with a direct measurement of the bar pattern speed host an ultrafast bar. These bars extend beyond the corotation radius and challenge our understanding of the orbital structure of barred galaxies. Most…

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