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We model and analyse the secular evolution of stellar bars in spinning dark matter (DM) haloes with the cosmological spin lambda ~ 0 -- 0.09. Using high-resolution stellar and DM numerical simulations, we focus on angular momentum exchange…

Astrophysics of Galaxies · Physics 2018-02-21 Angela Collier , Isaac Shlosman , Clayton Heller

We study the distribution of nearby thick disc and halo stars in subspaces defined by their characteristic orbital parameters. Our aim is to establish the origin of the structure reported in particular, in the $R_{\rm max}-z_{\rm max}$…

Astrophysics of Galaxies · Physics 2021-03-10 Helmer H. Koppelman , Jorrit H. J. Hagen , Amina Helmi

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

This is the third of a series of papers presenting the first attempt to analyze the growth of the bar instability in a consistent cosmological scenario. In the previous two articles we explored the role of the cosmology on stellar disks,…

Astrophysics · Physics 2009-11-13 Anna Curir , Paola Mazzei , Giuseppe Murante

Stellar bars in disk galaxies grow as stars in near circular orbits lose angular momentum to their environments, including their Dark Matter (DM) halo, and transform into elongated bar orbits. This angular momentum exchange during galaxy…

Astrophysics of Galaxies · Physics 2024-10-04 Sioree Ansar , Mousumi Das

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…

We show by numerical simulations that a purely stellar dynamical model composed of an exponential disc, a cuspy bulge, and an NFW halo with parameters relevant to the Milky Way Galaxy is subject to bar formation. Taking into account the…

Astrophysics of Galaxies · Physics 2016-08-17 Evgeny Polyachenko , Peter Berczik , Andreas Just

The halo plays a crucial role in the evolution of barred galaxies. Its near-resonant material absorbs angular momentum emitted from some of the disc particles and helps the bar become stronger. As a result, a bar (oval) forms in the inner…

Astrophysics · Physics 2015-06-24 E. Athanassoula

It has recently been proposed that if the Galactic dark matter halo were triaxial it would induce lumpiness in the velocity distribution of halo stars in the Solar Neighbourhood through orbital resonances. These substructures could…

Astrophysics of Galaxies · Physics 2018-04-12 Casper Hesp , Amina Helmi

Understanding radial migration is a crucial point to build relevant chemical and dynamical evolution models of the Milky Way disk. In this paper, we analyze a high-resolution N-body simulation of a Milky Way-type galaxy to study the role…

Astrophysics of Galaxies · Physics 2020-07-01 S. Khoperskov , P. Di Matteo , M. Haywood , A. Gomez , O. N. Snaith

Stellar bars are the most common non-axisymmetric structures in galaxies and their impact on the evolution of disc galaxies at all cosmological times can be significant. Classical theory predicts that stellar discs are stabilized against…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Kanak Saha , Thorsten Naab

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

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

A change in the mass of the Galaxy with time will leave its imprint on the motions of the stars, with stars having radially outward (mass loss) or inward (mass accretion) bulk motions. Here we test the feasibility of using the mean radial…

Astrophysics of Galaxies · Physics 2023-03-29 Sanjib Sharma , Joss Bland-Hawthorn , Joseph Silk , Celine Boehm

Using high resolution N-body simulations of stellar disks embedded in cosmologically motivated dark matter halos, we study the evolution of bars and the transfer of angular momentum between halos and bars. We find that dynamical friction…

Astrophysics · Physics 2009-11-07 Octavio Valenzuela , Anatoly Klypin

The spin of dark halos has been shown to significantly affect bar formation and evolution in disk galaxies. To understand the physical role of the halo spin on bar formation, we run $N$-body simulations of isolated, Milky Way-sized galaxies…

Astrophysics of Galaxies · Physics 2024-06-14 Dajeong Jang , Woong-Tae Kim

Recently, we determined a lower bound for the Milky Way mass in a point mass approximation. This result was obtained for most general spherically symmetric phase-space distribution functions consistent with a measured radial velocity…

Astrophysics of Galaxies · Physics 2016-11-04 Szymon Sikora , Łukasz Bratek , Joanna Jałocha , Marek Kutschera

Recent observations indicate that both the Milky Way bulge and inner halo exhibit angular momentum, although the origin and evolution of this prograde signature remain ambiguous. One plausible scenario involves secular evolution induced by…

Astrophysics of Galaxies · Physics 2025-06-17 Zhuohan Li , Chengdong Li , Gang Zhao , Ruizhi Zhang , Xiang-Xiang Xue

We investigate the evolution of two bars formed in fully self-consistent hydrodynamic simulations of the formation of Milky Way-mass galaxies. One galaxy shows higher central mass concentration and has a longer and stronger bar than the…

Astrophysics of Galaxies · Physics 2015-04-29 Takashi Okamoto , Mari Isoe , Asao Habe

Detailed analysis of kinematics of the Milky Way disk in the solar neighborhood based on the GAIA DR3 catalog reveals the existence of peculiarities in the stellar velocity distribution perpendicular to the galactic plane. We study the…

Astrophysics of Galaxies · Physics 2023-10-17 Vladimir Korchagin , Artem Lutsenko , Roman Tkachenko , Giovanni Carraro , Katherine Vieira