从流形到银条模型中的拉格朗日相干结构
From Manifolds to Lagrangian Coherent Structures in galactic bar models
摘要：
为了确定棒星系的整体形态，我们利用动力学系统工具研究了棒星系模型中不稳定拉格朗日点附近的动力学。我们的目标是在非自治模型的情况下，特别是与长期的演变，通过允许酒吧模式的速度随时间的推移而减少。我们扩展的概念广泛使用的流形的自治问题的拉格朗日相干结构（LCS），广泛用于流体动力学，其行为类似的不变流形驱动的运动。在适应LCS计算代码的银河系动力学问题，我们将其应用到自治和非自治的问题，与流形的结果，并确定最好的描述在非自治的情况下的运动的对象。我们看到，当应用于自治的情况下，应变线与稳定流形的第一个交叉点重合，而当使用长期模型时，应变线仍然显示与相应的稳定流形和能量急剧变化的区域相关联的最大排斥区域。由自治问题预测的星系的全球形态保持不变。
英文摘要：
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.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
