论文标题
大型星系磁盘中的稳定性和阻尼
Stability and Damping in the Disks of Massive Galaxies
论文作者
论文摘要
在最初的形成后，观察到磁盘星系在> 6 Gyr的周期内旋转稳定，这意味着在其旋转的时间尺度上，恒星和气云的任何大速度干扰都会迅速降低。但是，还知道，尽管进行了阻尼，但必须有一定程度的随机局部运动来稳定轨道，以防止脱落。这种阻尼的机制是通过固有引力相互作用的组合以及与与每个恒星相关的oort云和外容器对象的相互作用的组合提出的。对两个恒星之间的重力相互作用的分析是一个三体问题，因为恒星也位于银河系的大型虚拟质量周围。这些机制可能会在一个时间段内产生大型扰动的迅速阻尼，这在观察性外观时间的尺度上很短，但长期以来对具有小扰动的恒星的磁盘旋转时期的规模很长。这种机制还可以解释年轻恒星的银河系8-15〜km/s的局部观察到的平均扰动，而年龄较大的恒星的平均扰动和20-30〜km/s。
After their initial formation, disk galaxies are observed to be rotationally stable over periods of >6 Gyr, implying that any large velocity disturbances of stars and gas clouds are damped rapidly on the timescale of their rotation. However, it is also known that despite this damping, there must be a degree of random local motion to stabilize the orbits against degenerate collapse. A mechanism for such damping is proposed by a combination of inter-stellar gravitational interactions, and interactions with the Oort clouds and exo-Oort objects associated with each star. Analysis of the gravitational interactions between two stars is a three-body problem, because the stars are also in orbit round the large virtual mass of the galaxy. These mechanisms may produce rapid damping of large perturbations within a time period that is short on the scale of observational look-back time, but long on the scale of the disk rotational period for stars with small perturbations. This mechanism may also account for the locally observed mean perturbations in the Milky Way of 8-15~km/s for younger stars and 20-30~km/s for older stars.
