English
Related papers

Related papers: Bars within Bars in Galaxies

200 papers

The first results of the observational program of the study of 2D-kinematics in double-barred galaxies are presented. We show that, for the main part of the sample, the inner bars do not affect the circumnuclear stellar kinematics.…

Astrophysics · Physics 2007-05-23 A. V. Moiseev , J. R. Valdes , V. H. Chavushyan

Bars in galaxies may form not only through instability, but also as a result of an interaction with another galaxy. In particular, they may appear in disky dwarf galaxies interacting with Milky Way-like galaxies. Here we report the results…

Astrophysics of Galaxies · Physics 2018-11-29 Grzegorz Gajda , Ewa L. Łokas , E. Athanassoula

Although more than two-thirds of star-forming disk galaxies in the local universe are barred, some galaxies remain un-barred, occupying the upper half of the Hubble tuning fork diagram. Numerical simulations almost always produce bars…

Astrophysics of Galaxies · Physics 2018-05-16 Kanak Saha , Bruce Elmegreen

Galactic disks can form in asymmetric potentials of the assembling dark matter (DM) halos, giving rise to the first generation of gas-rich bars. Properties of these bars differ from canonical bars analyzed so far. Moreover, rapid disk…

Astrophysics · Physics 2008-12-05 Isaac Shlosman

Recent progress in the understanding of the role of bars and gravitational instabilities in galaxy disks is reviewed. It has been proposed that bars can produce mass transfer towards the center, and progressively metamorphose late-type…

Astrophysics · Physics 2007-05-23 F. Combes

The dynamical stability and evolution of disc galaxies with different disc thickness as well as various fraction and concentration of stellar counter-rotation is investigated with self-consistent numerical simulations. In particular,…

Astrophysics · Physics 2007-05-23 D. Friedli

The intrinsic photometric properties of inner and outer stellar bars within 17 double-barred galaxies are thoroughly studied through a photometric analysis consisting of: i) two-dimensional multi-component photometric decompositions, and…

Astrophysics of Galaxies · Physics 2020-04-01 A. de Lorenzo-Cáceres , J. Méndez-Abreu , B. Thorne , L. Costantin

We present results from an imaging survey of an unbiased sample of thirty-eight early-type (S0--Sa), low-inclination, optically barred galaxies in the field. Our goal was to find and characterize central stellar and gaseous structures:…

Astrophysics · Physics 2008-11-26 Peter Erwin , Linda S. Sparke

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

Bar structures can form internally due to the instability of their host galaxies or externally due to perturbations from other galaxies. We systematically quantify the growth timescales ($\tau_\mathrm{bar}$) of bars formed through these two…

Astrophysics of Galaxies · Physics 2025-07-01 Yirui Zheng , Juntai Shen , Xufen Wu , Bin-Hui Chen

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…

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

Bars are an elongated structure that extends from the centre of galaxies, and about one-third of disk galaxies are known to possess bars. These bars are thought to form either through a physical process inherent in galaxies, or through an…

Astrophysics of Galaxies · Physics 2019-06-26 Yongmin Yoon , Myungshin Im , Gwang-Ho Lee , Seong-Kook Lee , Gu Lim

In this and in a previous paper (Romero-Gomez et al. 2006) we propose a theory to explain the formation of both spirals and rings in barred galaxies using a common dynamical framework. It is based on the orbital motion driven by the…

Astrophysics · Physics 2009-11-13 M. Romero-Gomez , E. Athanassoula , J. J. Masdemont , C. Garcia-Gomez

Using a volume- and mass-limited (D < 30 Mpc, log (M_star/M_sun) $\geq 9.75$) sample of 155 barred S0-Sd galaxies, I determine the fraction with secondary structures within their bars. Some 20 +/- 3% have a separate inner bar, making them…

Astrophysics of Galaxies · Physics 2023-12-21 Peter Erwin

Secular evolution and fueling is driven by bars in spiral galaxies, and the related dynamical processes are reviewed. It is shown that gravity torques dominate over viscous torques, and produce gas infall to the center. In this infall, the…

Astrophysics · Physics 2009-11-10 Francoise Combes

We propose a theory to explain the formation of both spirals and rings in barred galaxies using a common dynamical framework. It is based on the orbital motion driven by the unstable equilibrium points of the rotating bar potential. Thus,…

Astrophysics · Physics 2016-11-23 M. Romero-Gomez

Isolated barred galaxies evolve by redistributing their internal angular momentum, which is emitted mainly at the inner disc resonances and absorbed mainly at the resonances in the outer disc and the halo. This causes the bar to grow…

Astrophysics · Physics 2007-05-23 E. Athanassoula

Double-barred galaxies are common in the local Universe, with approximately one third of barred spirals hosting an smaller, inner bar. Nested bars have been proposed as a mechanism for transporting gas to the very central regions of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 A. de Lorenzo-Cáceres , A. Vazdekis , J. A. L. Aguerri , E. M. Corsini , Victor P. Debattista

Inner bars are frequent structures in the local Universe and thought to substantially influence the nuclear regions of disc galaxies. In this study we explore the structure and dynamics of inner bars by deriving maps and radial profiles of…