论文标题
中子星的合并旋转定律和低-T/W的不稳定性
Merger-inspired rotation laws and the low-T/W instability in neutron stars
论文作者
论文摘要
通过实施受二进制中子恒星合并残留启发的差分旋转法则，我们考虑了旋转曲线对低T/W不稳定性的影响。我们利用牛顿重力的线性化动力学方程的时间演变来研究非轴对称振荡并识别不稳定模式。低T/W不稳定性的存在和演化是用规范能量和角动量监测的，而生长时间则是从进化的动能中提取的。新旋转法的结果突出了与通常被认为是J-Constant定律的相似之处。当振荡模式与恒星共旋转时（即，只要有一个模式的模式速度与散装角速度匹配）并在共同移动区域内长得更快。但是，新的配置文件添加了功能，例如问题的附加共存点，这会影响不稳定的开始。旋转定律在快速旋转模型中更大程度地影响了L = M = 2 F模式的振荡频率，但以任何旋转速率影响不稳定性生长时间。我们还确定了低t/w不稳定性似乎是由惯性模式触发的模型。我们讨论推断的定性行为可能在多大程度上具有观察性相关性。
Implementing a family of differential rotation laws inspired by binary neutron-star merger remnants, we consider the impact of the rotation profile on the low-T/W instability. We use time evolutions of the linearised dynamical equations, in Newtonian gravity, to study non-axisymmetric oscillations and identify the unstable modes. The presence and evolution of the low-T/W instability is monitored with the canonical energy and angular momentum, while the growth time is extracted from the evolved kinetic energy. The results for the new rotation laws highlight similarities with the commonly considered j-constant law. The instability sets in when an oscillation mode co-rotates with the star (i.e. whenever there is a point where the mode's pattern speed matches the bulk angular velocity) and grows faster deep inside the co-rotation region. However, the new profiles add features, like an additional co-rotation point to the problem, which affect the onset of instability. The rotation laws influence more drastically the oscillation frequencies of the l=m=2 f-mode in fast rotating models, but affect the instability growth time at any rotation rate. We also identify models where the low-T/W instability appears to be triggered by inertial modes. We discuss to what extent the inferred qualitative behaviour is likely to be of observational relevance.
