From Manifolds to Lagrangian Coherent Structures in galactic bar models
| Autor: | M. Romero-Gómez, Josep J. Masdemont, Patricia Sánchez-Martín |
|---|---|
| Přispěvatelé: | Universitat de Barcelona, Universitat Politècnica de Catalunya. Departament de Matemàtiques, Universitat Politècnica de Catalunya. SD - Sistemes Dinàmics de la UPC |
| Rok vydání: | 2018 |
| Předmět: |
Computation
Lagrangian point FOS: Physical sciences Astrophysics Dynamical system 01 natural sciences Dinàmica estel·lar 010305 fluids & plasmas Computer Science::Robotics Intersection 0103 physical sciences Invariant (mathematics) 010303 astronomy & astrophysics Stellar dynamics Physics Galactic structure kinematics and dynamics [Galaxies] Estructura galàctica Matemàtiques i estadística [Àrees temàtiques de la UPC] Astronomy and Astrophysics Galaxies Astrophysics - Astrophysics of Galaxies Stable manifold Galaxy Galàxies Barred spiral galaxy Classical mechanics spiral [galaxies] Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) structure [galaxies] |
| Zdroj: | Recercat. Dipósit de la Recerca de Catalunya instname UPCommons. Portal del coneixement obert de la UPC Universitat Politècnica de Catalunya (UPC) Dipòsit Digital de la UB Universidad de Barcelona |
| DOI: | 10.48550/arxiv.1807.06599 |
| Popis: | We study the dynamics near the unstable Lagrangian points in galactic bar models using dynamical system tools in order to determine the global morphology of a barred galaxy. We aim at the case of non-autonomous models, in particular with secular evolution, by allowing the bar pattern speed to decrease with time. We extend the concept of manifolds widely used in the autonomous problem to the Lagrangian Coherent Structures (LCS), widely used in fluid dynamics, which behave similar to the invariant manifolds driving the motion. After adapting the LCS computation code to the galactic dynamics problem, we apply it to both the autonomous and non-autonomous problems, relating the results with the manifolds and identifying the objects that best describe the motion in the non-autonomous case. We see that the strainlines coincide with the first intersection of the stable manifold when applied to the autonomous case, while, when the secular model is used, the strainlines still show the regions of maximal repulsion associated to both the corresponding stable manifolds and regions with a steep change of energy. The global morphology of the galaxy predicted by the autonomous problem remains unchanged. Comment: Accepted for publication in A&A, 15 pages, 21 figures |
| Databáze: | OpenAIRE |
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