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Related papers: Orbital Instabilities in a Triaxial Cusp Potential

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We use Laskar's frequency mapping technique to study the dynamics of triaxial galaxies with central density cusps and nuclear black holes. For ensembles of 10^4 orbits, we numerically compute the three fundamental frequencies of the motion,…

Astrophysics · Physics 2009-10-30 Monica Valluri , David Merritt

We study spherical and disk clusters in a near-Keplerian potential of galactic centers or massive black holes. In such a potential orbit precession is commonly retrograde, i.e. direction of the orbit precession is opposite to the orbital…

Astrophysics · Physics 2008-11-26 E. V. Polyachenko , V. L. Polyachenko , I. G. Shukhman

Recent studies have presented evidence that the Milky Way global potential may be nonspherical. In this case, the assembling process of the Galaxy may have left long lasting stellar halo kinematic fossils due to the shape of the dark matter…

Astrophysics of Galaxies · Physics 2015-05-27 Armando Rojas-Niño , Luis A. Martínez-Medina , Barbara Pichardo , Octavio Valenzuela

Due to the clumpy nature of the self gravitating gas composing the interstellar medium, it is not clear whether galactic gas dynamics can be discussed in terms of standard hydrodynamics. Nevertheless, it is clear that certain generic…

Astrophysics · Physics 2009-10-31 Amr El-Zant

The elliptical instability can take place in planetary cores and stars elliptically deformed by gravitational effects, where it generates large-scale three-dimensional flows assumed to be dynamo capable. In this work, we present the first…

Classical Physics · Physics 2013-09-10 David Cébron , Michael Le Bars , Pierre Maubert , Patrice Le Gal

The gravitational potentials of realistic galaxy models are in general non-integrable, in the sense that they admit orbits that do not have three independent isolating integrals of motion and are therefore chaotic. However, if chaotic…

Astrophysics of Galaxies · Physics 2021-09-29 R. Pascale , C. Nipoti , L. Ciotti

We describe the dynamics of a stream of equally spaced macroscopic particles in orbit around a central body (e.g. a planet or star). A co-orbital configuration of small bodies may be subject to gravitational instability, which takes the…

Earth and Planetary Astrophysics · Physics 2015-06-04 Henrik N. Latter , Hanno Rein , Gordon I. Ogilvie

Figure rotation substantially increases the fraction of stochastic orbits in triaxial systems. This increase is most dramatic in systems with shallow cusps showing that it is not a direct consequence of scattering by a central density cusp…

Astrophysics · Physics 2007-05-23 Monica Valluri

Recent results on chaos in triaxial galaxy models are reviewed. Central mass concentrations like those observed in early-type galaxies -- either stellar cusps, or massive black holes -- render most of the box orbits in a triaxial potential…

Astrophysics · Physics 2009-10-28 David Merritt

Orbits are the key building blocks of any density distribution and their study helps us understand the kinematical structure and the evolution of galaxies. Here we investigate orbits in a tidally induced bar of a dwarf galaxy, using an…

Astrophysics of Galaxies · Physics 2016-10-21 Grzegorz Gajda , Ewa L. Lokas , E. Athanassoula

Recent observational constraints restrict the strict applicability of stellar dynamics in spirals to a few rotation periods. However, stellar dynamics concepts such as periodic orbits are invaluable for understanding the various dynamical…

Astrophysics · Physics 2008-02-03 D. Pfenniger

It is well established that certain detached eclipsing binary stars exhibit apsidal motions whose value is in disagreement with with calculated deviations from Keplerian motion based on tidal effects and the general theory of relativity.…

Astrophysics · Physics 2009-11-07 S. A. Khodykin , A. I. Zakharov , W. L. Andersen

Hubble Space Telescope (HST) observations reveal that the density of stars in most elliptical galaxies rises toward the center in a power-law cusp. Many of these galaxies also contain central dark objects,possibly supermassive black holes.…

Astrophysics · Physics 2009-10-28 David Merritt

A new element is proposed to play a role in the evolution of extrasolar planetary systems: the tidal (or elliptical) instability. It comes from a parametric resonance and takes place in any rotating fluid whose streamlines are (even…

Solar and Stellar Astrophysics · Physics 2011-01-25 David Cébron , Claire Moutou , Michael Le Bars , Patrice Le Gal , R. Fares

We built two self-consistent models of triaxial, cuspy, rotating stellar systems adding rotation to non-rotating models presented in previous papers of this series. The final angular velocity of the material is not constant and varies with…

Astrophysics of Galaxies · Physics 2016-04-20 D. D. Carpintero , J. C. Muzzio

We study the dynamics in the neighborhood of simple and double unstable periodic orbits in a rotating 3D autonomous Hamiltonian system of galactic type. In order to visualize the four dimensional spaces of section we use the method of color…

Chaotic Dynamics · Physics 2017-01-09 M. Katsanikas , P. A. Patsis , G. Contopoulos

We have developed a method to construct realistic triaxial dynamical models for elliptical galaxies, allowing us to derive best-fitting parameters, such as the mass-to-light ratio and the black hole mass, and to study the orbital structure.…

Astrophysics · Physics 2007-05-23 Glenn van de Ven , Ellen Verolme , Michele Cappellari , Tim de Zeeuw

We investigate the triangular instability of a Batchelor vortex subjected to a stationary triangular strain field generated by three satellite vortices, in the presence of weak axial flow. The analysis combines theoretical predictions with…

Fluid Dynamics · Physics 2026-03-10 A. S. P. Ayapilla , Y. Hattori , S. Le Dizès

We investigate regular and chaotic two-dimensional (2D) and three-dimensional (3D) orbits of stars in models of a galactic potential consisting in a disk, a halo and a bar, to find the origin of boxy components, which are part of the bar or…

Astrophysics of Galaxies · Physics 2017-12-13 L. Chaves-Velasquez , P. A. Patsis , I. Puerari , Ch. Skokos , T. Manos

The tidal radius is commonly determined analytically by equating the tidal field of the galaxy to the gravitational potential of the cluster. Stars crossing this radius can move from orbiting the cluster centre to independently orbiting the…

Astrophysics of Galaxies · Physics 2014-11-11 Gareth F. Kennedy