存在涡旋陷阱时的脉冲星自转突变
Pulsar glitches in the presence of vortex traps
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中文总结 AI 辅助
研究脉冲星自转突变，采用Barnes - Hut近似模拟大量涡旋，探究非均匀钉扎时的突变情况，发现成熟脉冲星突变上升交错，年轻到中年恒星的相关配置会使突变大小分布呈双峰性，且涡旋分布会自发产生宏观不均匀性。
中文摘要 AI 辅助
脉冲星自转突变被认为是由角动量从内部的超流体通过涡旋雪崩传递到中子星地壳而引发的。此前通过模拟少量（约\(10^{3}\)）超流体涡旋的恒星已对该想法进行了定性验证。本文采用Barnes - Hut近似在合理时间内模拟多达\(10^{5}\)个涡旋，探究存在非均匀钉扎时的自转突变。中子星内壳在恒星自旋减速时预计会破裂，释放应力并导致地壳晶格重排，形成具有大钉扎能量的钉扎中心。模拟发现成熟脉冲星如船帆座脉冲星的突变上升呈交错状，年轻到中年的恒星如PSR J0537 - 6910会出现地震，导致新陷阱并解开现有陷阱中的涡旋，这种配置会使突变大小分布出现双峰性，模拟还表明在具有均匀钉扎位点的恒星中涡旋分布会自发产生宏观不均匀性。
英文摘要
Pulsar glitches are thought to originate when angular momentum is transferred to the crust of the neutron star from the superfluid enclosed within, mediated by vortex avalanches. This idea has been qualitatively validated in the existing literature by simulating a star with a small number ($\sim 10^{3}$) of superfluid vortices, subject to deceleration and uniform pinning. Here, we employ the Barnes-Hut approximation to simulate up to $10^{5}$ vortices in a reasonable time. Using the new setup, we probe glitches that originate in the presence of inhomogeneous pinning. The inner crust of a neutron star is expected to crack as the star spins down, relieving stresses and resulting in rearrangements within the crustal lattice. These regions become centres for pinning with large pinning energies. Many such vortex traps are expected to exist in mature pulsars like Vela. We simulate one such star and find that the rise of the glitch is now staggered, a clear signature of the trap network. In young to middle-aged stars like PSR J0537-6910, we expect quakes which result in new traps and also unpin the vortices in existing ones. We observe that such a configuration involving the simultaneous release of several traps could introduce a bimodality in the glitch-size distribution, a feature that has previously been reported for PSR J0537-6910. Our simulations also indicate that macroscopic inhomogeneities in the distribution of vortices could spontaneously develop in a star with uniform pinning sites.
