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Related papers: Bar instability in disk-halo systems

200 papers

We study gravitational instabilities in disks, with special attention to the most massive clumps that form because they are expected to be the progenitors of globular-type clusters. The maximum unstable mass is set by rotation and depends…

Astrophysics · Physics 2009-11-13 Andres Escala , Richard B. Larson

Disk-halo decompositions of galaxy rotation curves are generally performed in a parametric way. We construct self-consistent models of nonspherical isothermal halos embedding a zero-thickness disk, by assuming that the halo distribution…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-10 N. C. Amorisco , G. Bertin

We present a comprehensive series of $N$-body as well as $N$-body + SPH simulations to study the secular evolution of the structure of disk galaxies. Our simulations are organized in a hierarchy of increasing complexity, ranging from…

We characterize empirically the radial diffusion of stars in the plane of a typical barred disk galaxy by calculating the local spatial diffusion coefficient and diffusion time-scale for bulge-disk-halo N-body self-consistent systems which…

Astrophysics of Galaxies · Physics 2015-05-30 Maura Brunetti , Cristina Chiappini , Daniel Pfenniger

We study by computational means the dynamical stability against bar-mode deformation of rapidly and differentially rotating stars in a post-Newtonian approximation of general relativity. We vary the compaction of the star $M/R$ (where $M$…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Motoyuki Saijo , Masaru Shibata , Thomas W. Baumgarte , Stuart L. Shapiro

The formation of galactic discs and the efficiency of star formation within them are issues central to our understanding of galaxy formation. We have developed a detailed and versatile model of disc formation which combines the strengths of…

Astrophysics · Physics 2011-11-09 M. J. Stringer , A. J. Benson

We use high resolution collisionless $N$-body simulations to study the secular evolution of disk galaxies and in particular the final properties of disks that suffer a bar and perhaps a bar-buckling instability. Although we find that bars…

Astrophysics · Physics 2009-11-10 Victor P. Debattista , C. Marcella Carollo , Lucio Mayer , Ben Moore

The dark matter halo properties, for example, mass, spin and concentration play a significant role in the formation and evolution of bars in disk galaxies. This study highlights the importance of a new parameter: the dark matter halo…

Astrophysics of Galaxies · Physics 2024-06-26 Sandeep Kumar Kataria , Juntai Shen

The role of disk instabilities, such as bars and spiral arms, and the associated resonances, in growing bulges in the inner regions of disk galaxies have long been studied in the low-redshift nearby Universe. There it has long been probed…

Astrophysics of Galaxies · Physics 2015-12-30 Frederic Bournaud

We investigate the formation and evolution of galactic disks immersed in assembling live DM halos. Disk/halo components have been evolved from the cosmological initial conditions and represent the collapse of an isolated density…

Astrophysics · Physics 2009-11-13 Clayton Heller , Isaac Shlosman , Lia Athanassoula

In this paper we review the main and the most recent evidence for the presence of a core radius in the distribution of the dark matter around spiral galaxies. Their rotation curves, coadded according to the galaxy luminosity, conform to an…

Astrophysics · Physics 2007-05-23 Paolo Salucci , Annamaria Borriello

We analyze the physical justification of the picture proposed by Salvador-Sole et al. in these proceedings for the time evolution of the universal density profile of dark-matter halos. According to this picture, halos have at formation a…

Astrophysics · Physics 2007-05-23 G. Gonzalez-Casado , A. Raig , E. Salvador-Sole

Disk galaxies can exchange angular momentum and baryons with their host dark matter (DM) halos. These halos possess internal spin, `lambda', which is insignificant rotationally but does affect interactions between the baryonic and DM…

Astrophysics of Galaxies · Physics 2019-09-11 Angela Collier , Isaac Shlosman , Clayton Heller

We study the dynamics of galactic disk formation and evolution in 'realistic' LambdaCDM haloes with idealized baryonic initial conditions. We add rotating spheres of hot gas at z=1.3 to two fully cosmological dark-matter-only halo…

Astrophysics of Galaxies · Physics 2015-06-04 Michael Aumer , Simon D. M. White

Based on N-body simulations, we show that realistic galactic disks are subject to bending instabilities of fire-hose type when the disks are substantially self-gravitating, that is, if they contain dark matter distributed in the disk.…

Astrophysics · Physics 2007-05-23 Y. Revaz , D. Pfenniger

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

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

About two-thirds of the galactic disks exhibit a central ellipsoidal stellar component called the bar, with or without a gaseous counterpart. However, there are a few dwarf galaxies with purely gaseous bars: NGC3741, NGC2915 and DDO168.…

Astrophysics of Galaxies · Physics 2025-03-06 Anagha A G , Arunima Banerjee

We perform controlled N-body simulations of disc galaxies growing within live dark matter (DM) haloes to present-day galaxies that contain both thin and thick discs. We consider two types of models: a) thick-disc initial conditions to which…

Astrophysics of Galaxies · Physics 2017-06-14 Michael Aumer , James Binney

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