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Related papers: Warp evidences in precessing galactic bar models

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We establish a dynamical mechanism to explain the origin of the asymmetry between the arms observed in some barred disk galaxies, where one of the two arms emanating from the bar ends is very well defined, while the second one displays a…

Astrophysics of Galaxies · Physics 2023-01-31 P. Sánchez-Martín , C. García-Gómez , J. J. Masdemont , M. Romero-Gómez

In this and in a previous paper (Romero-Gomez et al. 2006) we propose a theory to explain the formation of both spirals and rings in barred galaxies using a common dynamical framework. It is based on the orbital motion driven by the…

Astrophysics · Physics 2009-11-13 M. Romero-Gomez , E. Athanassoula , J. J. Masdemont , C. Garcia-Gomez

We propose a theory to explain the formation of both spirals and rings in barred galaxies using a common dynamical framework. It is based on the orbital motion driven by the unstable equilibrium points of the rotating bar potential. Thus,…

Astrophysics · Physics 2016-11-23 M. Romero-Gomez

Warps are common vertical asymmetries that appear in the outer parts of the galactic discs, bending one part upwards and the other downwards. Many mechanisms can trigger warp formation, including tidal interactions. The interactions with…

Astrophysics of Galaxies · Physics 2024-09-18 Andressa Wille , Rubens E. G. Machado

Many barred galaxies, including the Large Magellanic Cloud (LMC), display strong lopsidedness and off-centre bars. The dynamical connection between bar-disc misalignments, internal mass asymmetries, and arm morphology is not yet fully…

Astrophysics of Galaxies · Physics 2026-05-20 P. Sánchez-Martín , M. López-Vilamajó , M. Romero-Gómez , J. J. Masdemont

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

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

Strong galactic bars produced in simulations tend to undergo a period of buckling instability that weakens and thickens them and forms a boxy/peanut structure in their central parts. This theoretical prediction has been confirmed by…

Astrophysics of Galaxies · Physics 2019-04-03 Ewa L. Lokas

A significant fraction of galaxies show warps in their discs, usually noticeable at its periphery. The exact origin of this phenomenon is not fully established, although multiple warp formation mechanisms are proposed. In this study, we…

Astrophysics of Galaxies · Physics 2026-02-03 Ilia V. Chugunov , Vladimir P. Reshetnikov , Alexander A. Marchuk

We present our investigation on the effect of warps on the extraction of rotation curves in edge-on galaxies. The method to derive the rotation curve from the position-velocity diagram in warped edge-on systems yields underestimated…

Astrophysics · Physics 2007-05-23 D. Vergani , G. Gentile , R. -J. Dettmar , G. Aronica , U. Klein

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

In a 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 2015-05-19 E. Athanassoula , M. Romero-Gomez , A. Bosma , J. J. Masdemont

We develop diagnostics to detect the presence and orientation of a bar in an edge-on disk, using its kinematical signature in the position-velocity diagram (PVD) of a spiral galaxy observed edge-on. Using a well-studied barred spiral galaxy…

Astrophysics · Physics 2009-10-31 M. Bureau , E. Athanassoula

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

Bars in galaxies may develop through a global instability or due to an interaction with another system. We study bar formation in disky dwarf galaxies orbiting a Milky Way-like galaxy. We employ $N$-body simulations to study the impact of…

Astrophysics of Galaxies · Physics 2017-06-28 Grzegorz Gajda , Ewa L. Lokas , E. Athanassoula

Using $N$-body simulations we study the buckling instability in a galactic bar forming in a Milky Way-like galaxy. The galaxy is initially composed of an axisymmetric, exponential stellar disk embedded in a spherical dark matter halo. The…

Astrophysics of Galaxies · Physics 2019-09-04 Ewa L. Lokas

We propose a new dynamical mechanism to account for the bar off-centering observed in many barred galaxies. It is based on the presence of a m=1 density wave, non-linearly excited by the strong m=2 component due to the linearly unstable bar…

Astrophysics · Physics 2007-05-23 F. Masset , M. Tagger

Recent ideas for the origin and persistence of the warps commonly observed in disc galaxies have focused on cosmic infall. We present N-body simulations of an idealized form of cosmic infall onto a disc galaxy and obtain a warp that closely…

Astrophysics · Physics 2009-11-11 Juntai Shen , J. A. Sellwood

In the manifold theory of spiral structure in barred galaxies, the usual assumption is that the spirals rotate with the same pattern speed as the bar. Here we generalize the manifold theory under the assumption that the spirals rotate with…

Chaotic Dynamics · Physics 2020-04-22 C. Efthymiopoulos , M. Harsoula , G. Contopoulos

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
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