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Related papers: Bar instability in cosmological halos

200 papers

We investigate the stability of trajectories in barred galaxies with mildly triaxial halos by means of Liapunov exponents. This method is perfectly suitable for time-dependent 3D potentials where surfaces of sections and other simple…

Astrophysics · Physics 2009-11-07 Amr El-Zant , Isaac Shlosman

Evolution of stellar bars in disk galaxies is accompanied by dynamical instabilities and secular changes. Following the vertical buckling instability, the bars are known to weaken dramatically and develop a pronounced boxy/peanut shape when…

Astrophysics · Physics 2009-11-13 Inma Martinez-Valpuesta , Isaac Shlosman , Clayton Heller

We investigate the Jeans instability of a galactic disk embedded in a dynamically responsive dark halo. It is shown that the disk-halo system becomes nominally Jeans unstable. On small scales the instability is suppressed, if the Toomre…

Astrophysics · Physics 2009-11-13 O. Esquivel , B. Fuchs

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

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

The spin of dark halos has been shown to significantly affect bar formation and evolution in disk galaxies. To understand the physical role of the halo spin on bar formation, we run $N$-body simulations of isolated, Milky Way-sized galaxies…

Astrophysics of Galaxies · Physics 2024-06-14 Dajeong Jang , Woong-Tae Kim

The characteristics of the galactic bars that are prone to suffer a damaging impact from a massive central black hole are examined using flat stellar disks. We construct three disk model groups that consist of exponential disks with one…

Astrophysics of Galaxies · Physics 2015-05-30 Shunsuke Hozumi

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

The properties of the bars formed by the bar instability are examined for flat stellar discs. The initial mass models chosen are Kuzmin--Toomre discs, for which two types of exact equilibrium distribution function (DF) are employed in order…

Astrophysics of Galaxies · Physics 2022-01-19 Shunsuke Hozumi

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

We present results of numerical N-body simulations of a galactic stellar disk embedded into a spherical dark halo. The non-linear dynamics of bending instabilities developing in the disk is studied. The bending modes, axisymmetric and not,…

Astrophysics · Physics 2007-05-23 N. V. Tyurina , A. V. Khoperskov , D. V. Bizyaev

We study the properties of two bars formed in fully cosmological hydrodynamical simulations of the formation of Milky Way-mass galaxies. In one case, the bar formed in a system with disc, bulge and halo components and is relatively strong…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Cecilia Scannapieco , Evangelia Athanassoula

We construct and evolve families of steady-state models of stellar disks embedded in live DM halos, in order to study the dynamical and secular phases of bar evolution. These models are tested against those published in the literature in…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Jorge Villa-Vargas , Isaac Shlosman , Clayton Heller

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 examine the observable properties of simulated barred galaxies including radial mass profiles, edge-on structure and kinematics, bar lengths and pattern speed evolution for detailed comparison to real systems. We have run several…

Astrophysics · Physics 2009-11-07 J. K. O'Neill , J. Dubinski

The dynamical stability of disk galaxies is sensitive to whether their anomalous rotation curves are caused by dark matter halos or Milgromian Dynamics (MOND). We investigate this by setting up a MOND model of M33. We first simulate it in…

Astrophysics of Galaxies · Physics 2022-03-08 Indranil Banik , Ingo Thies , Graeme Candlish , Benoit Famaey , Rodrigo Ibata , Pavel Kroupa

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…

We explore a series expansion method to calculate the modes of oscillations for a variety of uniformly rotating finite disks, either with or without a dark halo. Since all models have the same potential, this survey focuses on the role of…

Astrophysics · Physics 2011-05-23 P. Vauterin , H. Dejonghe

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

We study the formation of stellar bars using 145 simulations of disc galaxies embedded in live and static dark matter haloes. We use the exponential bar growth timescale, $\tau_{\rm bar}$, to quantify how disc structure and kinematics…

Astrophysics of Galaxies · Physics 2026-02-26 Matthew Frosst , Danail Obreschkow , Aaron Ludlow