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Related papers: Bar Formation from Galaxy Flybys

200 papers

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

We follow the formation and evolution of bars in N-body simulations of disc galaxies with gas and/or a triaxial halo. We find that both the relative gas fraction and the halo shape play a major role in the formation and evolution of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 E. Athanassoula , R. E. G. Machado , S. A. Rodionov

Although stellar bars are prevalent in local galaxies, unbarred galaxies constitute a significant fraction, particularly at high redshifts. While some galaxies are unbarred by nature due to stability against the bar instability, several…

Astrophysics of Galaxies · Physics 2026-03-30 Yufan Zhou , Zhiyuan Li , Óscar Jiménez-Arranz , Santi Roca-Fàbrega

We present a statistical analysis of flybys of dark matter halos compared to mergers using cosmological $N$-body simulations. We mainly focus on gravitationally interacting target halos with mass of $10^{10.8}-10^{13.0}h^{-1}M_{\odot}$, and…

Astrophysics of Galaxies · Physics 2019-12-18 Sung-Ho An , Juhan Kim , Jun-Sung Moon , Suk-Jin Yoon

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

We describe fully self-consistent N-body experiments of barred galaxies with massive halos. A rotating bar is braked through dynamical friction with the halo, which occurs on a short time scale when the central density of the halo is high.…

Astrophysics · Physics 2007-05-23 Victor P. Debattista , J. A. Sellwood

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

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

Central bars and spirals are known to strongly impact the evolution of their host galaxies, both in terms of dynamics and star formation. Their typically different pattern speeds cause them to regularly overlap, which induces fluctuations…

Bars in galaxies may develop through a global instability or due to an interaction with another system. We study bar formation in disky dwarf galaxies orbiting a Milky Way-like galaxy. We employ $N$-body simulations to study the impact of…

Astrophysics of Galaxies · Physics 2017-06-28 Grzegorz Gajda , Ewa L. Lokas , E. Athanassoula

Using three fiducial Nbody+SPH simulations, we follow the merging of two disk galaxies with a hot gaseous halo component each, and examine whether the merger remnant can be a spiral galaxy. The stellar progenitor disks are destroyed by…

Astrophysics of Galaxies · Physics 2016-04-27 E. Athanassoula , S. A. Rodionov , N. Peschken , J. C. Lambert

We present observational evidence for the inhibition of bar formation in dispersion-dominated (dynamically hot) galaxies by studying the relationship between galactic structure and host galaxy kinematics in a sample of 257 galaxies between…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Kartik Sheth , Jason Melbourne , Debra Meloy Elmegreen , Bruce G. Elmegreen , E. Athanassoula , Roberto G. Abraham , Ben Weiner

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

Most stars form in embedded clusters. Stellar flybys may affect the orbital architecture of the systems by exciting the eccentricity and causing dynamical instability. Since, incidentally, the timescale over which a cluster loses its…

Earth and Planetary Astrophysics · Physics 2015-06-12 Francesco Marzari , Giovanni Picogna

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

I discuss results from the COSMOS survey, showing that the fraction of disc galaxies that is barred decreases considerably with look-back time from z ~ 0.2 to z ~ 0.8. This decrease is more important for small mass and low luminosity…

Astrophysics · Physics 2008-02-04 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

Using high resolution N-body simulations of stellar disks embedded in cosmologically motivated dark matter halos, we study the evolution of bars and the transfer of angular momentum between halos and bars. We find that dynamical friction…

Astrophysics · Physics 2009-11-07 Octavio Valenzuela , Anatoly Klypin

By using $N$-body and hydro simulations, we study the formation and evolution of bars in galaxies with significant gas content focusing on the phenomenon of the buckling instability. The galaxies are initially composed of a spherical dark…

Astrophysics of Galaxies · Physics 2020-02-26 Ewa L. Lokas

About one third of early-type barred galaxies host small-scale secondary bars. The formation and evolution of such double-barred galaxies remain far from being well understood. In order to understand the formation of such systems, we…

Astrophysics of Galaxies · Physics 2015-05-27 Min Du , Juntai Shen , Victor P. Debattista