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Related papers: Oscillating dynamical friction on galactic bars by…

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Galaxy models have long predicted that galactic bars slow down by losing angular momentum to their postulated dark haloes. When the bar slows down, resonance sweeps radially outwards through the galactic disc while growing in volume,…

Astrophysics of Galaxies · Physics 2023-08-04 Rimpei Chiba , Ralph Schönrich

We investigate the complex interactions between the stellar disc and the dark-matter halo during bar formation and evolution using N-body simulations with fine temporal resolution and optimally chosen spatial resolution. We find that the…

Astrophysics of Galaxies · Physics 2016-10-17 Michael S. Petersen , Martin D. Weinberg , Neal Katz

Dynamical friction implies a consistency check on any system where dark matter particles are hypothesised to explain orbital dynamics requiring more mass under Newtonian gravity than is directly detectable. Introducing the assumption of a…

Astrophysics of Galaxies · Physics 2025-11-07 X. Hernandez , Pavel Kroupa

Why do galactic bars rotate with high pattern speeds, when dynamical friction should rapidly couple the bar to the massive, slowly rotating dark halo? This longstanding paradox may be resolved by considering the dynamical interactions…

Astrophysics · Physics 2009-10-31 S. Tremaine , J. P. Ostriker

We study evolution of galactic bars using suite of very high-resolution zoom-in cosmological simulations of galaxies at z ~ 9-2. Our models were chosen to lie within similar mass DM halos, log(Mvir/Mo) ~ 11.65 +- 0.05, at z=6, 4, and 2, in…

Astrophysics of Galaxies · Physics 2022-08-03 Da Bi , Isaac Shlosman , Emilio Romano-Diaz

In the context of increasing appreciation for the coupling between the Galactic bar and the halo, we introduce a new framework using stars trapped in resonance with the bar to probe the Galactic dark matter subhalo population. Since…

Astrophysics of Galaxies · Physics 2026-03-06 Elliot Y. Davies , Adam M. Dillamore , Vasily Belokurov , Lina Necib

The dynamical friction experienced by a body moving in a gaseous medium is different from the friction in the case of a collisionless stellar system. Here we consider the orbital evolution of a gravitational perturber inside a gaseous…

Astrophysics · Physics 2009-10-31 F. J. Sanchez-Salcedo , A. Brandenburg

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

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…

Galactic bars are found in the majority of disc galaxies. They rotate nearly rigidly with an angular frequency called pattern speed. Previous idealised simulations have shown that bar pattern speed decreases with time due to dynamical…

Astrophysics of Galaxies · Physics 2024-12-11 Marcin Semczuk , Walter Dehnen , Ralph Schönrich , E. Athanassoula

Simulations predict that bars in galaxies should slow down over time. This is often attributed to the exchange of angular momentum between the bar and other regions of the galaxy, such as the outer disc and dark matter halo, which implies…

Astrophysics of Galaxies · Physics 2026-04-07 Tobias Géron , Kai Zhu , Steph Campbell , Chris Lintott , R. J. Smethurst , Behzad Tahmasebzadeh

We study nonlinear response of spinning dark matter (DM) halos to dynamic and secular evolution of stellar bars in the embedded galactic disks, using high-resolution numerical simulations. For a sequence of halos with the cosmological spin…

Astrophysics of Galaxies · Physics 2019-09-04 Angela Collier , Isaac Shlosman , Clayton Heller

Resonant torques couple stellar bars to dark matter halos. Here we use high-resolution numerical simulations to demonstrate long-term angular momentum transfer between stellar bars and dark matter orbits of varying orientation. We show that…

Astrophysics of Galaxies · Physics 2021-07-07 Angela Collier , Ann-Marie Madigan

More than 50 per cent of present-day massive disc galaxies show a rotating stellar bar. Their formation and dynamics have been widely studied both numerically and observationally. Although numerical simulations in the $\Lambda$CDM…

Astrophysics of Galaxies · Physics 2022-01-17 Ornela F. Marioni , Mario G. Abadi , Stefan Gottlöber , Gustavo Yepes

We use high resolution numerical simulations in order to analyze the stellar bar evolution in spinning dark matter (DM) halos. Previous works have shown that the halo spin has a substantial effect on the bar evolution and can lead to bar…

Astrophysics of Galaxies · Physics 2023-09-13 Xingchen Li , Isaac Shlosman , Clayton Heller , Daniel Pfenniger

In this paper, we systematically explore the impact of a galactic bar on the inspiral time-scale of a massive object (MO) within a Milky Way-like galaxy. We integrate the orbit of MOs in a multi-component galaxy model via a semi-analytical…

Astrophysics of Galaxies · Physics 2022-03-14 Elisa Bortolas , Matteo Bonetti , Massimo Dotti , Alessandro Lupi , Pedro R. Capelo , Lucio Mayer , Alberto Sesana

We study the mechanisms and evolutionary phases of bar formation in n-body simulations of a stellar disc and dark matter halo system using harmonic basis function expansion analysis to characterize the dynamical mechanisms in bar evolution.…

Astrophysics of Galaxies · Physics 2019-03-21 Michael S. Petersen , Martin D. Weinberg , Neal Katz

Angular momentum redistribution within barred galaxies drives their dynamical evolution. Angular momentum is emitted mainly by near-resonant material in the bar region and absorbed by resonant material mainly in the outer disc and in the…

Astrophysics · Physics 2009-11-10 E. Athanassoula

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

Dynamical friction leads to an orbital decay of massive objects like young compact star clusters or Massive Black Holes in central regions of galaxies. The dynamical friction force can be well approximated by Chandrasekhar's standard…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-01 A. Just , F. M. Khan , P. Berczik , A. Ernst , R. Spurzem