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Related papers: Spinning dark matter halos promote bar formation

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I follow a bar from its formation, via its evolution, to its destruction and, perhaps, regeneration. I discuss the main features at each stage and particularly the role of the halo. Bars can form even in sub-maximum discs. In fact, such…

Astrophysics · Physics 2007-05-23 E. Athanassoula

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

More than 50 per cent of present-day massive disc galaxies show a rotating stellar bar. Their formation and dynamics have been widely studied both numerically and observationally. Although numerical simulations in the $\Lambda$CDM…

Astrophysics of Galaxies · Physics 2022-01-17 Ornela F. Marioni , Mario G. Abadi , Stefan Gottlöber , Gustavo Yepes

The evolution of a stellar bar transforms not only the galactic disk, but also the host dark matter halo. We present high resolution, fully self-consistent N-body simulations that clearly demonstrate that dark matter halo central density…

Astrophysics · Physics 2009-11-10 Kelly Holley-Bockelmann , Martin Weinberg , Neal Katz

We investigate the effects of halo kinematics on the dynamics of stellar discs by simulating the evolution of isolated disc-halo systems from equilibrium initial conditions. Our main results come from four simulations where the initial disc…

Astrophysics of Galaxies · Physics 2023-12-05 Robin Joshi , Lawrence M. Widrow

In this paper I argue that, far from necessarily hindering bar formation in disc galaxies, inner haloes may stimulate it. This constitutes a new instability mechanism by which bars can grow. To show this I use a number of N-body simulations…

Astrophysics · Physics 2007-05-23 E. Athanassoula

While bars are common in disk galaxies, their formation conditions are not well understood. We use $N$-body simulations to study bar formation and evolution in isolated galaxies consisting of a stellar disk, a classical bulge, and a dark…

Astrophysics of Galaxies · Physics 2023-01-25 Dajeong Jang , Woong-Tae Kim

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

Recent JWST observations claim the existence of a significant fraction of bars in the kinematically hotter and thicker disk at high redshift Universe. These observations challenge the current understanding of disk stability in galaxies…

Astrophysics of Galaxies · Physics 2025-12-29 Sandeep Kumar Kataria

Barred galaxies constitute about two thirds of observed disc galaxies. Bars affect not only the mass distribution of gas and stars, but also that of the dark matter. An elongation of the inner dark matter halo is known as the halo bar. We…

Astrophysics of Galaxies · Physics 2024-05-28 Daniel A. Marostica , Rubens E. G. Machado , E. Athanassoula , T. Manos

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

We investigate the evolution of two bars formed in fully self-consistent hydrodynamic simulations of the formation of Milky Way-mass galaxies. One galaxy shows higher central mass concentration and has a longer and stronger bar than the…

Astrophysics of Galaxies · Physics 2015-04-29 Takashi Okamoto , Mari Isoe , Asao Habe

We study the detailed structure of galaxies at redshifts z > 2 using cosmological simulations with improved modeling of the interstellar medium and star formation. The simulations follow the formation and dissociation of molecular hydrogen,…

Astrophysics of Galaxies · Physics 2012-09-21 Marcel Zemp , Oleg Y. Gnedin , Nickolay Y. Gnedin , Andrey V. Kravtsov

Cosmological N-body simulations indicate that the dark matter haloes of galaxies should be generally triaxial. Yet, the presence of a baryonic disc is believed to alter the shape of the haloes. Here we aim to study how bar formation is…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-19 Rubens E. G. Machado , E. Athanassoula

Using the SDSS spectroscopic sample, we estimate the dark matter halo spin parameter lambda for ~53,000 disk galaxies for which MOPED star formation histories are available. We investigate the relationship between spin and total stellar…

Astrophysics · Physics 2009-11-13 Zachory K. Berta , Raul Jimenez , Alan F. Heavens , Ben Panter

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…

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

Firstly, we demonstrate that unusually large outer HI spiral arms observed in NGC 2915 can form in an extended gas disk embedded in a massive triaxial dark matter halo with slow figure rotation, through the strong gravitational torque of…

Astrophysics · Physics 2007-05-23 K. Bekki , K. C. Freeman

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

Recent developments in computer hardware and software enable researchers to simulate the self-gravitating evolution of galaxies at a resolution comparable to the actual number of stars. Here we present the results of a series of such…

Astrophysics of Galaxies · Physics 2018-04-04 Michiko S. Fujii , Jeroen Bédorf , Junichi Baba , Simon Portegies Zwart