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Related papers: Oscillating dynamical friction on galactic bars by…

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We explore the impact of dynamical friction on scales where the linear growth factor and the spherical collapse model can be applied and show its influence on the evolution of perturbations. In particular, considering smooth and clustering…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-25 Francesco Pace , Orlando Luongo , Antonino Del Popolo

We investigate the dynamical response of dispersion-dominated halo populations to a rotating galactic bar, focusing on how the underlying halo phase space distribution function (DF), and in particular the orbital anisotropy, shapes resonant…

Astrophysics of Galaxies · Physics 2026-05-29 Paula Gherghinescu , Francesca Fragkoudi , Alis Deason

It is likely that cold molecular clouds form at high redshift, before galaxies. Considering these cold clouds instead of hot homogeneous gas as the main baryonic component of proto-galactic halos may affect several issues during galaxy…

Astrophysics · Physics 2009-11-07 B. Semelin , F. Combes

Isolated barred galaxies evolve by redistributing their angular momentum, which, emitted by material in the inner disc at resonance with the bar, can be absorbed by resonant material in the outer disc, or in the halo. The amount of angular…

Astrophysics · Physics 2009-11-07 E. Athanassoula

The evolution of a small satellite inside a more massive truncated isothermal spherical halo is studied using both the Theory of Linear Response for dynamical friction and N-Body simulations. The analytical approach includes the effects of…

Astrophysics · Physics 2009-10-31 Monica Colpi , Lucio Mayer , Fabio Governato

The main goal of this paper is to set up a numerical laboratory for the study of the slow evolution of the density and of the pressure tensor profiles of an otherwise collisionless stellar system, as a result of the interactions with a…

Astrophysics · Physics 2009-11-07 G. Bertin , T. Liseikina , F. Pegoraro

We study dynamics of bars in models of disk galaxies embeded in realistic dark matter halos. We find that disk thickness plays an important, if not dominant, role in the evolution and structure of the bars. We also make extensive numerical…

Astrophysics · Physics 2015-05-13 A. Klypin , O. Valenzuela , P. Colin , T. Quinn

We draw attention to the bright galaxies that do not show a bar in their structure but have a flocculent spiral structure. Using the THINGS' and HERACLES' kinematic data for four barless galaxies (NGC~2841, NGC~3512, NGC~5055, NGC~7331) we…

Astrophysics of Galaxies · Physics 2023-09-06 Daria Zakharova , Natalia Ya. Sotnikova , Anton A. Smirnov , Sergey S. Savchenko

Galactic bars, made up of elongated and aligned stellar orbits, can lose angular momentum via resonant torques with dark matter particles in the halo and slow down. Here we show that if a stellar bar is decelerated to zero rotation speed,…

Astrophysics of Galaxies · Physics 2023-05-12 Angela Collier , Ann-Marie Madigan

Barred galaxies constitute about two thirds of observed disc galaxies. Bars affect not only the mass distribution of gas and stars, but also that of the dark matter. An elongation of the inner dark matter halo is known as the halo bar. We…

Astrophysics of Galaxies · Physics 2024-05-28 Daniel A. Marostica , Rubens E. G. Machado , E. Athanassoula , T. Manos

I present some new results, from simulations and observations, of the constraints bar pattern speeds place on the dark matter content of disk galaxies.

Astrophysics · Physics 2007-05-23 Victor P. Debattista

Classical bulges and stellar bars are common features in disk galaxies and serve as key tracers of galactic evolution. Angular momentum exchange at bar resonances drives secular morphological changes throughout the disk, including bar…

Over a handful of rotation periods, dynamical processes in barred galaxies induce non-axisymmetric structure in dark matter halos. Using n-body simulations of a Milky Way-like barred galaxy, we identify both a trapped dark-matter component,…

High Energy Physics - Phenomenology · Physics 2017-02-01 Michael S. Petersen , Neal Katz , Martin D. Weinberg

Within the dark matter paradigm, explaining observed orbital dynamics at galactic level through the inclusion of a dominant dark halo, implies also the necessary appearance of dynamical friction effects. Satellite galaxies, globular…

Astrophysics of Galaxies · Physics 2019-02-28 X. Hernandez

We investigate the connection between the vertical structure of stellar discs and the formation of bars using high-resolution simulations of galaxies in isolation and in the cosmological context. In particular, we simulate a suite of…

Astrophysics of Galaxies · Physics 2019-02-27 Jacob S. Bauer , Lawrence M. Widrow

We present a new implementation of fuzzy dark matter (FDM) dynamical friction within the galpy framework, enabling orbital integrations of globular clusters (GCs) across a broad range of halo-to-GC mass ratios and boson masses. In this…

Astrophysics of Galaxies · Physics 2026-04-08 Adrian Szpilfidel , Pierre Boldrini , Jo Bovy , Paola Di Matteo

A live halo plays an active role in the formation and evolution of bars by participating in the angular momentum redistribution which drives the dynamical evolution. Angular momentum is emitted mainly by near-resonant material in the bar…

Astrophysics · Physics 2009-11-11 E. Athanassoula

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

The dark matter halos in $\Lambda$CDM cosmological simulations are triaxial and highly flattened. In many cases, these triaxial equilibria are also tumbling slowly, typically about their short axes, with periods of order a Hubble time.…

Astrophysics of Galaxies · Physics 2015-05-13 John Dubinski , Dalia Chakrabarty

We study the structure and evolution of the galactic bar's resonant phase-space in self-consistent N-body simulations of the Milky Way, with and without perturbations from the Sagittarius dwarf galaxy. In an idealized disk evolution model…

Astrophysics of Galaxies · Physics 2026-04-03 Rimpei Chiba , Michiko Fujii , Junichi Baba , John Dubinski , Ralph Schönrich