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Related papers: Star formation and bar instability in cosmological…

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Strong galactic bars produced in simulations tend to undergo a period of buckling instability that weakens and thickens them and forms a boxy/peanut structure in their central parts. This theoretical prediction has been confirmed by…

Astrophysics of Galaxies · Physics 2019-04-03 Ewa L. Lokas

We investigate the bar formation process using $N$-body simulations across the Toomre's parameter $Q_{min}$ and central mass concentration (CMC), focusing principally on the formation timescale. Of importance is that, as suggested by…

Astrophysics of Galaxies · Physics 2025-03-20 Tirawut Worrakitpoonpon

We conduct numerical experiments by evolving gaseous/stellar disks embedded in live dark matter halos aiming at quantifying the effect of gas spatial resolution and gas content on the bar evolution. Model sequences have been constructed…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Jorge Villa-Vargas , Isaac Shlosman , Clayton Heller

Star formation depends on the available gaseous "fuel" as well as galactic environment, with higher specific star formation rates where gas is predominantly molecular and where stellar (and dark matter) densities are higher. The partition…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Eve C. Ostriker

Stellar bars are the most common non-axisymmetric structures in galaxies and their impact on the evolution of disc galaxies at all cosmological times can be significant. Classical theory predicts that stellar discs are stabilized against…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Kanak Saha , Thorsten Naab

Recent observational constraints restrict the strict applicability of stellar dynamics in spirals to a few rotation periods. However, stellar dynamics concepts such as periodic orbits are invaluable for understanding the various dynamical…

Astrophysics · Physics 2008-02-03 D. Pfenniger

The role of dark matter halos in galaxy disk evolution is reviewed, in particular the stabilisation of disks through self-gravity reduction, or the bar development through angular momentum exchange. Triaxial dark halos tend to weaken bars.…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-19 F. Combes

We perform several high resolution N-Body/SPH simulations of low surface brightness galaxies (LSBs) embedded in cold dark matter halos to study how likely is bar formation in such systems. The behavior of various collisionless galaxy models…

Astrophysics · Physics 2009-11-07 Lucio Mayer , James Wadsley

We study formation and evolution of bar-disk systems in fully self-consistent cosmological simulations of galaxy formation in the LCDM WMAP3 Universe. In a representative model we find that the first generation of bars form in response to…

Astrophysics · Physics 2009-11-13 Emilio Romano-Diaz , Isaac Shlosman , Clayton Heller , Yehuda Hoffman

A significant fraction of local galaxies exhibit stellar bars, non-axisymmetric structures composed of stars, gas, and dust. Identifying key differences between the properties of barred and unbarred galaxies can uncover clues about the…

Astrophysics of Galaxies · Physics 2025-05-23 Paula D. López , Cecilia Scannapieco , Sofía A. Cora , Ignacio D. Gargiulo

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

We analyze the evolution of stellar bars in galactic disks in mildly triaxial flat-core and cuspy CDM halos. We use tailored simulations of rigid and live halos which include the feedback from disk/bar onto the halo in order to test the…

Astrophysics · Physics 2009-11-10 Ingo Berentzen , Isaac Shlosman , Shardha Jogee

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…

The time evolution of barred structures is examined under the influence of the external forces exerted by a spherical halo and by prolate halos. In particular, galaxy disks are placed in the plane including the major axis of prolate halos,…

Astrophysics · Physics 2009-10-31 Makoto Ideta , Shunsuke Hozumi

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

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

Past studies have long emphasised the key role played by galactic stellar bars in the context of disc secular evolution, via the redistribution of gas and stars, the triggering of star formation, and the formation of prominent structures…

[Abridged] Star and planet formation are the complex outcomes of gravitational collapse and angular momentum transport mediated by protostellar and protoplanetary disks. In this review we focus on the role of gravitational instability in…

Solar and Stellar Astrophysics · Physics 2016-10-05 Kaitlin M. Kratter , Giuseppe Lodato

We demonstrate that growth of stellar bars in spinning dark matter halos is heavily suppressed in the secular phase of evolution, using numerical simulations of isolated galaxies. In a representative set of models, we show that for values…

Astrophysics of Galaxies · Physics 2015-06-18 Stacy Long , Isaac Shlosman , Clayton Heller

Using data from the Gaia satellite's Radial Velocity Spectrometer Data Release 3 (RVS, DR3), we find a new and robust feature in the phase space distribution of halo stars. It is a prominent ridge at constant energy and with angular…

Astrophysics of Galaxies · Physics 2023-07-21 Adam M. Dillamore , Vasily Belokurov , N. Wyn Evans , Elliot Y. Davies