3D chaotic diffusion in barred spiral galaxies
3D chaotic diffusion in barred spiral galaxies
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DOI：
10.1093/mnras/stt1640
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发表时间：
2013-12
影响因子：
4.8
通讯作者：
G. Contopoulos;M. Harsoula
中科院分区：
文献类型：
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作者：
G. Contopoulos;M. Harsoula
研究了棒旋星系N体模型中三维轨道的扩散。初始条件接近稳定或不稳定周期轨道的3D混沌轨道，在共转内部，在4D相空间中保持被困在旋转环面或沿着不稳定渐近流形附近，并且与宇宙的年龄相比，在通过“阿诺德扩散”向外扩散并最终逃离系统之前，在很长一段时间内支持棒的形状。在最初的扩散阶段，这些轨道支撑着星系螺旋结构的内部。另一方面，初始条件在共转之外的3D混沌轨道可以保持接近并沿着不稳定的渐近流形（在根本不存在旋转环面的情况下），支持星系螺旋结构的外部部分大约是哈勃时间的1/3。
We study the diffusion of 3D orbits in anN-body model simulating a barred spiral galaxy. 3D chaotic orbits with initial conditions close to stable or unstable periodic orbits, inside corotation, stay trapped close to rotational tori or along unstable asymptotic manifolds, in the 4D phase space, and support the shape of the bar for very long times compared to the age of the Universe, before getting diffused outwards through ‘Arnold diffusion’ and finally escape from the system. During their initial time of diffusion, these orbits support the inner parts of the spiral structure of the galaxy. On the other hand 3D chaotic orbits with initial conditions outside corotation can stay close and along unstable asymptotic manifolds (in cases when no rotational tori exist at all), supporting the outer parts of the spiral structure of the galaxy for approximately 1/3 of the Hubble time.