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Related papers: Dynamical Decoupling of Nested Bars: Self-Gravitat…

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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

A substantial fraction of disk galaxies is double-barred. We analyze the dynamical stability of such nested bar systems by means of Liapunov exponents,by fixing a generic model and varying the inner (secondary) bar mass. We show that there…

Astrophysics · Physics 2009-11-10 Amr El-Zant , Isaac Shlosman

We investigate gas dynamics in the presence of a double inner Lindblad resonance within a barred disk galaxy. Using an example of a prominent spiral, M100, we reproduce the basic central morphology, including four dominant regions of star…

Astrophysics · Physics 2015-06-24 Isaac Shlosman

Asymmetries in galactic potentials, either self-induced, or caused by a passing companion, play an important role in global gas dynamics in galaxies. In particular, they are able to trigger gas inflow, which in turn feeds nuclear activity.…

Astrophysics · Physics 2007-05-23 Witold Maciejewski

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

We investigate rapid mass supply process by nested bars in the Galaxy by numerical simulation. We simulate gas flow in the whole galaxy disk with nested bars, which are the outer bar and the inner bar, especially with highly spatial…

Astrophysics · Physics 2011-02-11 Daisuke Namekata , Asao Habe , Hidenori Matsui , Takayuki R. Saitoh

We analyze how the orbital support of the inner bar in a double-barred galaxy (nested bars) depends on the angular velocity (i.e. pattern speed) of this bar. We study orbits in seven models of double bars using the method of invariant…

Astrophysics of Galaxies · Physics 2015-05-19 Witold Maciejewski , Emma E. Small

We run self-consistent simulations of Milky Way-sized, isolated disk galaxies to study formation and evolution of a stellar bar as well as a nuclear ring in the presence of gas. We consider two sets of models with cold or warm disks that…

Astrophysics of Galaxies · Physics 2019-02-13 Woo-Young Seo , Woong-Tae Kim , SungWon Kwak , Pei-Ying Hsieh , Cheongho Han , Phil F. Hopkins

The role of gas in the mass assembly at the nuclei of galaxies is still subject to some uncertainty. Stellar nuclear discs bridge the gap between the large-scale galaxy and the central massive objects that reside there. Using a high…

Astrophysics of Galaxies · Physics 2015-06-23 David R. Cole , Victor P. Debattista , Peter Erwin , Samuel W. F. Earp , Rok Roskar

To investigate the role of bars in the chemical evolution of isolated disc galaxies, we performed a series of 39 gas dynamical simulations of isolated barred and unbarred galaxies with various masses, initial gas fractions, and AGN feedback…

Astrophysics of Galaxies · Physics 2018-05-02 Hugo Martel , Christian Carles , Fidèle Robichaud , Sara L. Ellison , David J. Williamson

The effects of gas accretion on spiral disk dynamics and stability are studied through N-body simulations, including star formation and gas/stars mass exchange. The detailed processes of bar formation, bar destruction and bar re-formation…

Astrophysics · Physics 2009-11-07 F. Bournaud , F. Combes

We explore how the physical properties of disc galaxies relate to the presence of bars using data from the SDSS-IV MaNGA survey. By combining internal kinematical properties and environmental diagnostics, we find that barred galaxies are…

Astrophysics of Galaxies · Physics 2025-12-25 Erik Aquino-Ortíz , Bernardo Cervantes-Sodi , Karol Chim-Ramirez

A wide-spread belief that nested bars enhance gas inflow to the galactic centre has recently been contradicted by dynamical models in which inner bars seem to prohibit such inflow. Can the existing models of dynamically possible double bars…

Astrophysics · Physics 2007-05-23 Witold Maciejewski

We carry out a detailed orbit analysis of gravitational potentials selected at different times from an evolving self-consistent model galaxy consisting of a two-component disk (stars+gas) and a live halo. The results are compared with a…

Astrophysics · Physics 2009-10-30 I. Berentzen , C. H. Heller , I. Shlosman , K. J. Fricke

Double bars have been proposed as a means of transporting molecular gas past inner Lindblad resonances into the nuclear regions, where it can fuel active or starburst nuclei. Thus far, the existence of double bars has been determined…

Astrophysics · Physics 2009-11-07 Glen Petitpas , Christine Wilson

High-resolution observations of the inner regions of barred disk galaxies have revealed many asymmetrical, small-scale central features, some of which are best described as secondary bars. Because orbital time-scales in the galaxy center…

Astrophysics · Physics 2009-10-31 Witold Maciejewski , Linda S. Sparke

Gaseous nuclear rings are large-scale coherent structures commonly found at the centres of barred galaxies. We propose that they are an accumulation of gas at the inner edge of an extensive gap that forms around the Inner Lindblad Resonance…

Astrophysics of Galaxies · Physics 2024-01-09 Mattia C. Sormani , Emanuele Sobacchi , Jason L. Sanders

We develop a dynamical theory for the origin of nuclear rings in barred galaxies. In analogy with the standard theory of accretion discs, our theory is based on shear viscous forces among nested annuli of gas. However, the fact that gas…

We discuss the mechanism(s) of bar formation in isolated and tidally interacting disk galaxies using the results of idealized collisionless Nbody simulations of the galaxies. In order to better understand the mechanism, we investigate…

Astrophysics of Galaxies · Physics 2022-11-09 Kenji Bekki

When bars form within galaxy formation simulations in the standard cosmological context, dynamical friction with dark matter (DM) causes them to rotate rather slowly. However, almost all observed galactic bars are fast in terms of the ratio…

Astrophysics of Galaxies · Physics 2021-03-30 Mahmood Roshan , Indranil Banik , Neda Ghafourian , Ingo Thies , Benoit Famaey , Elena Asencio , Pavel Kroupa