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Related papers: Formation timescales for stellar bars in diverse g…

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We investigate the complex interactions between the stellar disc and the dark-matter halo during bar formation and evolution using N-body simulations with fine temporal resolution and optimally chosen spatial resolution. We find that the…

Astrophysics of Galaxies · Physics 2016-10-17 Michael S. Petersen , Martin D. Weinberg , Neal Katz

Using N-body simulations, we examine the impact of dark matter (DM) halo resolution and gravitational softening on bar formation. We generate isolated disk-halo systems with fixed stellar disk parameters, varying the number of halo…

Astrophysics of Galaxies · Physics 2026-03-04 S. Kwak , I. Minchev , M. Steinmetz , S. K. Yi

Simulations and observations of galactic bars suggest they do not commonly evolve into bulges, although it is possible that the earliest bars formed bulges long ago, when galaxies were smaller, denser, and had more gas. The most highly…

Astrophysics · Physics 2015-06-24 Bruce G. Elmegreen

Different mechanisms driving bar structure formation indicate that bar origins should be distinguishable in the stellar populations of galaxies. To study how these origins affect different bar morphologies and impact stellar orbits and…

Astrophysics of Galaxies · Physics 2023-10-12 Elizabeth J. Iles , Alex R. Pettitt , Takashi Okamoto , Daisuke Kawata

For several decades it has been known that stellar bars in disc galaxies can be triggered by interactions, or by internal processes such as dynamical instabilities. In this work, we explore the differences between these two mechanisms using…

Simulations have shown that bars are subject to a vertical buckling instability that transforms thin bars into boxy or peanut-shaped structures, but the physical conditions necessary for buckling to occur are not fully understood. We use…

Astrophysics of Galaxies · Physics 2017-08-23 Zhao-Yu Li , Luis C. Ho , Aaron J. Barth

We have measured the radial light profiles and global shapes of bars using two-dimensional 3.6 $\mu m $ image decompositions for 144 face-on barred galaxies from the Spitzer Survey of Stellar Structure in Galaxies (S4G). The bar surface…

One third of present-day spirals host optically visible strong bars that drive their dynamical evolution. However, the fundamental question of how bars evolve over cosmological times has yet to be addressed, and even the frequency of bars…

We present a chemo-dynamical $N$-body/hydrodynamic simulation of an isolated Milky Way-like galaxy to investigate how bar formation influences star formation rates, stellar migration, and the resulting age and metallicity distributions of…

Astrophysics of Galaxies · Physics 2025-05-23 Junichi Baba

Having once thought that we understood how some galaxies were barred and had difficulty accounting for the absence of bars in others, it now seems that we have the opposite problem. Most real galaxies have centres dense enough to inhibit…

Astrophysics · Physics 2007-05-23 J. A. Sellwood

Bars are an elongated structure that extends from the centre of galaxies, and about one-third of disk galaxies are known to possess bars. These bars are thought to form either through a physical process inherent in galaxies, or through an…

Astrophysics of Galaxies · Physics 2019-06-26 Yongmin Yoon , Myungshin Im , Gwang-Ho Lee , Seong-Kook Lee , Gu Lim

We present a dynamical model for the formation and evolution of a massive disk galaxy, within a growing dark halo whose mass evolves according to cosmological simulations of structure formation. The galactic evolution is simulated with a…

Astrophysics · Physics 2009-11-07 Markus Samland , Ortwin Gerhard

We study the mechanisms and evolutionary phases of bar formation in n-body simulations of a stellar disc and dark matter halo system using harmonic basis function expansion analysis to characterize the dynamical mechanisms in bar evolution.…

Astrophysics of Galaxies · Physics 2019-03-21 Michael S. Petersen , Martin D. Weinberg , Neal Katz

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

Classical bulges and stellar bars are common features in disk galaxies and serve as key tracers of galactic evolution. Angular momentum exchange at bar resonances drives secular morphological changes throughout the disk, including bar…

Recent observations of high-redshift galaxies ($z \lesssim 7$) reveal that a substantial fraction have turbulent, gas-rich disks with well-ordered rotation and elevated levels of star formation. In some instances, disks show evidence of…

Astrophysics of Galaxies · Physics 2024-05-03 Joss Bland-Hawthorn , Thor Tepper-Garcia , Oscar Agertz , Christoph Federrath

The bar structure in disk galaxies models is formed by different families of orbits; however, it is not clear how these families of orbits support the bar throughout its secular evolution. Here, we analyze the orbital structure on three…

Astrophysics of Galaxies · Physics 2023-08-04 Diego Valencia-Enríquez , Ivânio Puerari , Leonardo Chaves-Velasquez

We construct a model for the Milky Way Galaxy composed of a stellar disc and bulge embedded in a dark-matter halo. All components are modelled as $N$-body systems with up to 8 billion equal-mass particles and integrated up to an age of…

Astrophysics of Galaxies · Physics 2018-10-17 Michiko S. Fujii , Jeroen Bédorf , Junichi Baba , Simon Portegies Zwart

Almost two-thirds of disk galaxies in the local universe host bars, which serve as important drivers of secular evolutionary processes. While cosmological simulations are powerful tools to study the formation and evolution of galaxies, they…

Astrophysics of Galaxies · Physics 2020-12-09 Dongyao Zhao , Min Du , Luis C. Ho , Victor P. Debattista , Jingjing Shi

The process of bar formation, evolution and destruction is still a controversial topic regarding galaxy dynamics. Numerical simulations show that these phenomena strongly depend on physical and numerical parameters. In this work, we study…

Astrophysics of Galaxies · Physics 2025-07-25 Alejandro López Gómez , Ruslan Gabbasov , Isaura Luisa Fuentes-Carrera