Title: Short-period pulsar oscillations following a glitch Show Chinese title

Title: 脉冲星 glitch 后的短周期振荡

Abstract: Following a glitch, the crust and magnetized plasma in the outer core of a neutron star are believed to rapidly establish a state of co-rotation within a few seconds by process analogous to classical Ekman pumping. However, in ideal magnetohydrodynamics, a final state of co-rotation is inconsistent with conservation of energy of the system. We demonstrate that, after the Ekman-like spin up is completed, magneto-inertial waves continue to propagate throughout the star, exciting torsional oscillations in the crust and plasma. The crust oscillation is irregular and quasi-periodic, with a dominant frequency of the order of seconds. Crust oscillations commence after an Alfv\'en crossing time, approximately half a minute at the magnetic pole, and are subsequently damped by the electron viscosity over approximately an hour. In rapidly rotating stars, the magneto-inertial spectrum in the core approaches a continuum, and crust oscillations are damped by resonant absorption analogous to quasi-periodic oscillations in magnetars. The oscillations predicted are unlikely to be observed in timing data from existing radio telescopes, but may be visible to next generation telescope arrays. Show Chinese abstract

Abstract: 在一次异常事件后，被认为中子星外核的地壳和磁化等离子体会通过类似于经典埃克曼泵浦的过程，在几秒钟内迅速进入共同旋转的状态。然而，在理想磁流体力学中，最终的共同旋转状态与系统的能量守恒相矛盾。 我们证明了，在埃克曼式加速完成后，磁惯性波继续在整个恒星中传播，激发地壳和等离子体的扭转振动。地壳振动是不规则且准周期性的，主要频率约为秒级。 地壳振动在阿尔芬穿越时间之后开始，磁极处大约半分钟，并在约一个小时后被电子粘度逐渐阻尼。 在快速自转的恒星中，核心的磁惯性谱接近连续谱，地壳振动则通过类似磁星的准周期振荡的共振吸收而被阻尼。 所预测的振动不太可能在现有射电望远镜的计时数据中观测到，但可能会被下一代望远镜阵列观测到。