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Related papers: Resonance sweeping by a decelerating Galactic bar

200 papers

Context: Resonances in the stellar orbital motion under perturbations from spiral arms structure play an important role in the evolution of the disks of spiral galaxies. The epicyclic approximation allows the determination of the…

Astrophysics of Galaxies · Physics 2016-10-20 Tatiana A. Michtchenko , Ronaldo S. S. Vieira , Douglas A. Barros , Jacques R. D. Lépine

Both the three-dimensional density of red clump giants and the gas kinematics in the inner Galaxy indicate that the pattern speed of the Galactic bar could be much lower than previously estimated. Here, we show that such slow bar models are…

Astrophysics of Galaxies · Physics 2016-12-21 Giacomo Monari , Benoit Famaey , Arnaud Siebert , Aurore Duchateau , Thibault Lorscheider , Olivier Bienaymé

We have modelled the nonlinear development of the secular bar-mode instability that is driven by gravitational radiation-reaction (GRR) forces in rotating neutron stars. In the absence of any competing viscous effects, an initially…

Astrophysics · Physics 2009-11-10 Shangli Ou , Joel E. Tohline , Lee Lindblom

I present results from the modeling of stellar bars in nearly 300 barred galaxies in the local universe through parametric multi-component multi-band image fitting. The surface brightness radial profile of bars is described using a Sersic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Dimitri A. Gadotti

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

The bar pattern speed of the LMC has been measured using Gaia data, suggesting the presence of a slow pattern, perhaps not rotating at all. Numerical simulations of interacting LMC-SMC systems were able to reproduce a bar stoppage. Here, we…

Astrophysics of Galaxies · Physics 2025-11-05 V. Araya , L. Chemin , O. Jimenez-Arranz , M. Romero-Gomez

We extract the resonant orbits from an N-body bar that is a good representation of the Milky Way, using the method recently introduced by Molloy et al. (2015). By decomposing the bar into its constituent orbit families, we show that they…

Astrophysics of Galaxies · Physics 2015-10-28 Matthew Molloy , Martin C. Smith , N. Wyn Evans , Juntai Shen

Within Rotation Curves (RC) is encoded the kinematical state of the stellar disc as well as information about the dynamical mechanisms driving the secular evolution of galaxies. To explain the characteristic features of RCs that arise by…

Astrophysics of Galaxies · Physics 2020-06-15 Luis A. Martinez-Medina , Barbara Pichardo , Antonio Peimbert

Hydro-dynamical modeling of the inner Galaxy suggest that the radius of the outer Lindblad resonance (OLR) of the Galactic bar lies in the vicinity of the Sun. How does this resonance affect the distribution function in the outer parts of a…

Astrophysics · Physics 2009-05-29 Walter Dehnen

Bars and spiral arms have played an important role as constraints on the dynamics and on the distribution of dark matter in the optical parts of disk galaxies. Dynamics linked to the dissipative nature of gas, and its transformation into…

Astrophysics · Physics 2016-01-27 Daniel Pfenniger , Yves Revaz

Using N-body simulations, we examine the impact of dark matter (DM) halo resolution and gravitational softening on bar formation. We generate isolated disk-halo systems with fixed stellar disk parameters, varying the number of halo…

Astrophysics of Galaxies · Physics 2026-03-04 S. Kwak , I. Minchev , M. Steinmetz , S. K. Yi

We analyze bars formed in $N$-body simulations to investigate two key aspects of stellar kinematic structure of barred galaxies: the angular distributions of the radial and azimuthal components of stellar velocities, and the impact of bars…

Astrophysics of Galaxies · Physics 2025-07-22 Seungwon Baek , Woong-Tae Kim , Dajeong Jang , Taehyun Kim

We report idealized simulations that mimic the growth of galaxy disks embedded in responsive halos and bulges. The disks manifested an almost overwhelming tendency to form strong bars that we found very difficult to prevent. We found that…

Astrophysics of Galaxies · Physics 2017-10-11 Joel C. Berrier , J. A. Sellwood

While it has long been known that a large number of short-lived transient spirals can cause stellar migration, here we report that another mechanism is also effective at mixing disks of barred galaxies. The resonance overlap of the bar and…

Astrophysics of Galaxies · Physics 2014-11-20 I. Minchev , B. Famaey

We study, using direct orbit integrations, the kinematic response of the outer stellar disk to the presence of a central bar, as in the Milky-Way. We find that the bar's outer Lindblad resonance (OLR) causes significant perturbations of the…

Astrophysics · Physics 2007-05-23 Gerhard M"uhlbauer , Walter Dehnen

Previous work has related the Galactic bar to structure in the local stellar velocity distribution. Here we show that the bar also influences the spatial gradients of the velocity vector via the Oort constants. By numerical integration of…

Astrophysics of Galaxies · Physics 2010-02-10 Ivan Minchev , Jason Nordhaus , Alice Quillen

Young stellar bars in disk galaxies experience a vertical buckling instability which terminates their growth and thickens them, resulting in a characteristic peanut/boxy shape when viewed edge on. Using N-body simulations of galactic disks…

Astrophysics · Physics 2009-11-10 Inma Martinez-Valpuesta , Isaac Shlosman

Models of the Galaxy with analytical Ferrers bars can reproduce the residual velocities of OB-associations in the Sagittarius, Perseus and Local System stellar-gas complexes located within 3 kpc solar neighborhood. Ferrers ellipsoids with…

Astrophysics of Galaxies · Physics 2019-02-12 Anna M. Melnik

Bars drive the dynamical evolution of disk galaxies by redistributing mass and angular momentum, and they are ubiquitous in present-day spirals. Early studies of the Hubble Deep Field reported a dramatic decline in the rest-frame optical…

Co-moving groups of stars (streams) are well known in the velocity space of the disc near the Sun. Many are thought to arise from resonances with the Galactic bar or spiral arms. In this work, we search for similar moving groups in the…

Astrophysics of Galaxies · Physics 2025-07-16 Adam M. Dillamore , Jason L. Sanders , Vasily Belokurov , Hanyuan Zhang