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Related papers: Orbital structure in barred spiral galaxies

200 papers

High resolution N-body simulations using different codes and initial condition techniques reveal two different behaviours for the rotation frequency of transient spiral arms like structures. Whereas unbarred disks present spiral arms nearly…

We study the dynamics of 2D and 3D barred galaxy analytical models, focusing on the distinction between regular and chaotic orbits with the help of the Smaller ALigment Index (SALI), a very powerful tool for this kind of problems. We…

Astrophysics · Physics 2013-03-26 T. Manos , E. Athanassoula

The chaotic or ordered character of orbits in galactic models is an important issue, since it can influence dynamical evolution. This distinction can be achieved with the help of the Smaller Alingment Index - (SALI). We describe here…

Astrophysics · Physics 2009-11-11 T. Manos , E. Athanassoula

In an effort to better understand the formation and evolution of barred galaxies, we have examined the properties of equatorial orbits in the effective potential of one model of a rapidly rotating, steady-state gas-dynamical bar that has…

Astrophysics · Physics 2009-11-06 Eric Barnes , Joel E. Tohline

We summarize recent developments in the use of spectral methods for analyzing large numbers of orbits in N-body simulations to obtain insights into the global phase space structure of dark matter halos. The fundamental frequencies of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Monica Valluri , Victor P. Debattista , Tom Quinn , Ben Moore

Studies of dynamical stability (chaotic versus regular motion) in galactic dynamics often rely on static analytical models of the total gravitational potential. Potentials based upon self-consistent N-body simulations offer more realistic…

Astrophysics of Galaxies · Physics 2016-04-08 Rubens E. G. Machado , T. Manos

A method which we have developed for determining corotation radii, has allowed us to map in detail the radial resonant structures of barred spiral galaxies. Here we have combined this information with new determinations of the bar strength…

Astrophysics of Galaxies · Physics 2019-01-23 Joan Font , John E. Beckman , Phil A. James , Panos A. Patsis

In the presence of a strong $m=2$ component in a rotating galaxy, the phase space structure near corotation is shaped to a large extent by the {\it invariant manifolds} of the short period family of unstable periodic orbits terminating at…

Astrophysics · Physics 2016-04-26 Nikos Voglis , Panagiotis Tsoutsis , Christos Efthymiopoulos

Self-consistent N-body simulations are efficient tools to study galactic dynamics. However, using them to study individual trajectories (or ensembles) in detail can be challenging. Such orbital studies are important to shed light on global…

Astrophysics of Galaxies · Physics 2015-06-17 T. Manos , Rubens E. G. Machado

The regular or chaotic dynamics of an analytical realistic three dimensional model composed of a spherically symmetric central nucleus, a bar and a flat disk is investigated. For describing the properties of the bar we introduce a new…

Astrophysics of Galaxies · Physics 2015-11-18 Christof Jung , Euaggelos E. Zotos

The distinction between chaotic and regular behavior of orbits in galactic models is an important issue and can help our understanding of galactic dynamical evolution. In this paper, we deal with this issue by applying the techniques of the…

Astrophysics of Galaxies · Physics 2015-05-27 T. Manos , E. Athanassoula

We propose a new theory to explain the formation of spiral arms and of all types of outer rings in barred galaxies. We have extended and applied the technique used in celestial mechanics to compute transfer orbits. Thus, our theory is based…

Astrophysics · Physics 2007-12-31 M. Romero-Gomez , E. Athanassoula , J. J. Masdemont , C. Garcia-Gomez

The dynamical evolution of barred galaxies depends crucially on the fraction and their spacial distribution of chaotic orbits in them. In order to distinguish between the two kinds of orbits, we use the Smaller Alignment Index (SALI)…

Astrophysics · Physics 2007-05-23 T. Manos , E. Athanassoula

We interpret simulations of secularly-evolving disc galaxies through orbit morphology. Using a new algorithm that measures the volume of orbits in real space using a tessellation, we rapidly isolate commensurate (resonant) orbits. We…

Astrophysics of Galaxies · Physics 2021-04-30 Michael S. Petersen , Martin D. Weinberg , Neal Katz

Recently, many orbital studies in barred galaxy potentials have revealed the existence of orbits which are not trapped around x1 tree orbits, but could be potentially appropriate building blocks for bars. These findings question the…

Astrophysics of Galaxies · Physics 2020-02-18 P. A. Patsis , E. Athanassoula

In this series of papers, we propose a theory to explain the formation and properties of rings and spirals in barred galaxies. The building blocks of these structures are orbits guided by the manifolds emanating from the unstable Lagrangian…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 E. Athanassoula , M. Romero-Gomez , A. Bosma , J. J. Masdemont

We propose a theory to explain the formation of spiral arms and of all types of outer rings in barred galaxies, extending and applying the technique used in celestial mechanics to compute transfer orbits. Thus, our theory is based on the…

Astrophysics · Physics 2015-05-13 M. Romero-Gomez , E. Athanassoula , J. J. Masdemont , C. Garcia-Gomez

We present an update to the frequency analysis method for measuring the properties of a galactic bar. The method involves computing the fundamental frequencies of orbits in rotating, N-body-derived potential models, classifying the stars as…

Astrophysics of Galaxies · Physics 2026-05-13 Zachary Langford , Robyn Sanderson , Madeline Lucey , Jason A. S. Hunt

The manifold theory of barred-spiral structure provides a dynamical mechanism explaining how spiral arms beyond the ends of galactic bars can be supported by chaotic flows extending beyond the bar's co-rotation zone. We discuss its…

Astrophysics of Galaxies · Physics 2019-01-23 C. Efthymiopoulos , P. E. Kyziropoulos , R. I. Paez , K. Zouloumi , G. A. Gravvanis

We investigate the evolution of orbital shapes at the Inner Lindblad Resonance region of a rotating three-dimensional bar, the mass of which is growing with time. We evaluate in time-dependent models, during a 5 Gyr period, the importance…

Astrophysics of Galaxies · Physics 2021-10-27 Thanos Manos , Charalampos Skokos , Panos Patsis