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Related papers: Pattern speed evolution and bar reformation

200 papers

One of the main properties of galactic bars is their rotation (or pattern) speed, which is driven by both internal galactic properties, as well as external interactions. To assess the influence of these internal and external drivers on bar…

Astrophysics of Galaxies · Physics 2026-01-30 Alex Merrow , Francesca Fragkoudi , Rob J. J. Grand , Marie Martig

Many strong simulated galactic bars experience buckling instability, which manifests itself as a vertical distortion out of the disk plane, and later dissipates. Using a simulation of an isolated Milky Way-like galaxy, I demonstrate that…

Astrophysics of Galaxies · Physics 2025-07-09 Ewa L. Lokas

Most late-type stars in the solar neighborhood have velocities similar to the local standard of rest (LSR), but there is a clearly separated secondary component corresponding to a slower rotation and a mean outward motion. Detailed…

Astrophysics · Physics 2009-10-31 Walter Dehnen

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

The rate of internally-driven evolution of galaxy discs is strongly affected by the lifetimes of the spiral patterns they support. Evolution is much faster if the spiral patterns are recurrent short-lived transients rather than long-lived,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 J. A. Sellwood

We investigate the orbital structure in a class of 3D models of barred galaxies. We consider different values of the pattern speed, of the strength of the bar and of the parameters of the central bulge of the galactic model. The morphology…

Astrophysics · Physics 2009-11-07 Ch. Skokos , P. A. Patsis , E. Athanassoula

Bars play a major role in driving the evolution of disk galaxies and in shaping their present properties. They cause angular momentum to be redistributed within the galaxy, emitted mainly from (near-)resonant material at the inner Lindblad…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-30 E. Athanassoula

Identifying the structure of our Galaxy has always been fraught with difficulties, and while modern surveys continue to make progress building a map of the Milky Way, there is still much to understand. The arm and bar features are important…

Astrophysics of Galaxies · Physics 2020-01-08 Alex R. Pettitt , Sarah E. Ragan , Martin C. Smith

We investigate the variation of bar strength with central velocity dispersion in a sample of barred spiral galaxies. The bar strength is characterized by $Q_g$, the maximal tangential perturbation associated with the bar, normalized by the…

Astrophysics · Physics 2014-11-18 M. Das , E. Laurikainen , H. Salo , R. Buta

A brief review is given of different methods used to determine the pattern speeds of the Galactic bar and spiral arms. The Galactic bar rotates rapidly, with corotation about halfway between the Galactic center and the Sun, and outer…

Astrophysics of Galaxies · Physics 2010-03-15 Ortwin Gerhard

The life of disk galaxies is likely punctuated with the birth (spontaneous or induced), the aging (quick or slow), and the death (sudden or progressive) of bars. These events are responsible for various major changes of the galaxy which…

Astrophysics · Physics 2007-05-23 D. Friedli

Both the three-dimensional density of red clump giants and the gas kinematics in the inner Galaxy indicate that the pattern speed of the Galactic bar could be much lower than previously estimated. Here, we show that such slow bar models are…

Astrophysics of Galaxies · Physics 2016-12-21 Giacomo Monari , Benoit Famaey , Arnaud Siebert , Aurore Duchateau , Thibault Lorscheider , Olivier Bienaymé

We present simulations of the gaseous and stellar material in several different galaxy mass models under the influence of different tidal fly-bys to assess the changes in their bar and spiral morphology. Five different mass models are…

Astrophysics of Galaxies · Physics 2018-01-10 Alex R. Pettitt , James W. Wadsley

Interstellar turbulence is driven over a wide range of scales by processes including spiral arm instabilities and supernovae, and it affects the rate and morphology of star formation, energy dissipation, and angular momentum transfer in…

Astrophysics · Physics 2016-01-27 Bruce G. Elmegreen

Stellar bars are elongated structures in disk galaxies that can torque and funnel gas inward, influencing galaxy evolution. While strong bars are known to induce rapid inflow, the impact of weaker bars remains less certain. We collected…

We investigate pattern speeds in spiral galaxies where the structure is induced by an interaction with a companion galaxy. We perform calculations modeling the response of the stellar and/or gaseous components of a disc. Generally we do not…

Astrophysics of Galaxies · Physics 2010-02-08 C. L. Dobbs

Spirals in galaxies have long been thought to be caused by gravitational instability in the stellar component of the disk, but discerning the precise mechanism had proved elusive. Tidal interactions, and perhaps bars, may provoke some…

Astrophysics of Galaxies · Physics 2022-09-28 J. A. Sellwood , Karen L. Masters

Some 30% of disc galaxies have a pronounced central bar feature in the disc plane and many more have weaker features of a similar kind. Kinematic data indicate that the bar constitutes a major non-axisymmetric component of the mass…

Astrophysics · Physics 2009-11-11 J. A. Sellwood , A. Wilkinson

It is well-established that strong bars rotating in dense halos generally slow down as they lose angular momentum to the halo through dynamical friction. Angular momentum exchanges between the bar and halo particles take place at…

Astrophysics · Physics 2009-11-13 J. A. Sellwood , Victor P. Debattista

The distribution of gravitational torques and bar strengths in the local Universe is derived from a detailed study of 163 galaxies observed in the near-infrared. The results are compared with numerical models for spiral galaxy evolution. It…

Astrophysics · Physics 2009-11-07 David L. Block , Frederic Bournaud , Francoise Combes , Ivanio Puerari , Ron Buta