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Related papers: Resonance sweeping by a decelerating Galactic bar

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Bars are common galactic structures in the local universe that play an important role in the secular evolution of galaxies, including the Milky Way. In particular, the velocity distribution of individual stars in our galaxy is useful to…

We select a sample of galaxies from the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7) where galaxies are classified, through visual inspection, as hosting strong bars, weak bars or as unbarred galaxies, and make use of HI mass and…

Astrophysics of Galaxies · Physics 2017-01-23 Bernardo Cervantes Sodi

Based on a high quality $N$-body simulation of a double bar galaxy model, we investigate the evolution of the bar properties, including their size, strength and instantaneous pattern speed derived by using three distinct methods: the…

Astrophysics of Galaxies · Physics 2018-07-11 Yu-Ting Wu , Daniel Pfenniger , Ronald E. Taam

Action-based dynamical modelling, using stars as dynamical tracers, is an excellent diagnostic to estimate the underlying axisymmetric matter distribution of the Milky Way. However, the Milky Way's bar causes non-axisymmetric resonance…

Astrophysics of Galaxies · Physics 2023-06-27 Soumavo Ghosh , Wilma H. Trick , Gregory M. Green

We examine the bar instability in models with an exponential disk and a cuspy NFW-like dark matter (DM) halo inspired by cosmological simulations. Bar evolution is studied as a function of numerical resolution in a sequence of models…

Astrophysics · Physics 2015-05-13 John Dubinski , Ingo Berentzen , Isaac Shlosman

A bar rotating in a pressure-supported halo generally loses angular momentum and slows down due to dynamical friction. Valenzuela & Klypin report a counter-example of a bar that rotates in a dense halo with little friction for several Gyr,…

Astrophysics · Physics 2015-06-24 J. A. Sellwood , Victor P. Debattista

Galaxy modelling is greatly simplified by assuming the existence of a global system of angle-action coordinates. Unfortunately, global angle-action coordinates do not exist because some orbits become trapped by resonances, especially where…

Astrophysics of Galaxies · Physics 2016-08-17 James Binney

We study by computational means the dynamical stability against bar-mode deformation of rapidly and differentially rotating stars in a post-Newtonian approximation of general relativity. We vary the compaction of the star $M/R$ (where $M$…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Motoyuki Saijo , Masaru Shibata , Thomas W. Baumgarte , Stuart L. Shapiro

Supermassive black holes in the centre of galaxies dominate the gravitational potential of their surrounding stellar clusters. In these dense environments, stars follow nearly Keplerian orbits, which get slowly distorted as a result of the…

The dynamics of stellar streams in rotating barred potentials is explained for the first time. Naturally, neighbouring stream stars reach pericentre at slightly different times. In the presence of a rotating bar, these neighbouring stream…

Astrophysics of Galaxies · Physics 2018-11-02 Kohei Hattori , Denis Erkal , Jason L. Sanders

The $^{12}$CO $(J=1\rightarrow0)$ velocity fields of a sample of 20 nearby spiral galaxies, selected from the CO Multi-line Imaging of Nearby Galaxies (COMING) legacy project of Nobeyama Radio Observatory, have been analyzed by Fourier…

In a galaxy merger, the stars tidally stripped from the satellite and accreted onto the host galaxy undergo phase mixing and form finely-grained structures in the phase space. However, these fragile structures may be destroyed in the…

Astrophysics of Galaxies · Physics 2023-03-06 Elliot Y. Davies , Adam M. Dillamore , Eugene Vasiliev , Vasily Belokurov

We study the dynamical interactions of mass systems in equilibrium under their own gravity that mutually exert and experience gravitational forces. The method we employ is to model the dynamical evolution of two isolated bars, hosted within…

Astrophysics of Galaxies · Physics 2017-07-12 F. Garzon , M. Lopez-Corredoira

Observations of the spatial distribution and kinematics of young stars in the Galactic centre can be interpreted as showing that the stars occupy one, or possibly two, discs of radii ~0.05-0.5 pc. The most prominent (`clockwise') disc…

Astrophysics of Galaxies · Physics 2012-04-03 Bence Kocsis , Scott Tremaine

Gaia DR2 has delivered full-sky 6-D measurements for millions of stars, and the quest to understand the dynamics of our Galaxy has entered a new phase. Our aim is to reveal and characterize the kinematic sub-structure of the different…

Astrophysics of Galaxies · Physics 2018-11-14 P. Ramos , T. Antoja , F. Figueras

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

For the first time, we investigate the resonant structure of $N$-body galactic bar at the stage of buckling using action-angle variables. We studied the evolution of vertical actions ($J_z$) and angles associated with vertical resonance…

Astrophysics of Galaxies · Physics 2025-06-05 Viktor D. Zozulia , Natalia Ya. Sotnikova , Anton A. Smirnov

Decoding the key dynamical processes that shape the Galactic disk structure is crucial for reconstructing the Milky Way's evolution history. The second Gaia data release unveils a novel wave pattern in the $L_Z-\langle V_R\rangle$ space,…

Astrophysics of Galaxies · Physics 2024-11-19 Chengye Cao , Zhao-Yu Li , Ralph Schönrich , Teresa Antoja

The radial velocity signature of stellar noise is small, around the meter-per-second, but already too much for the detection of Earth mass planets in habitable zones. In this paper, we address the important role played by observational…

Earth and Planetary Astrophysics · Physics 2015-05-20 Xavier Dumusque , Stephane Udry , Christophe Lovis , Nuno C. Santos , Mario J. F. P. G. Monteiro

We use perturbation theory and bifurcation theory to analyze the dynamical behavior of resonances, associated to a model describing a particle moving within a ring around a celestial object. The central body is modeled as a homogeneous…

Mathematical Physics · Physics 2025-07-22 Alessandra Celletti , Irene De Blasi , Sara Di Ruzza
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