标题： 俘获效应对中子星外壳中的应力和脉冲星 glitches 的影响 显示英文标题

标题： Effect of entrainment on stress and pulsar glitches in neutron star crust

摘要： 脉冲星频率 glitches（频率突变）的应力积累被认为可以归因于各种机制，其中最有效的涉及旋转中子星（被磁制动减速的固态外壳）内层的中子超流体的差速旋转。 在这种情况下，通常认为这种应力是由于超流体涡旋与壳核的钉扎效应引起的。 然而，几年前有人提出，即使钉扎效应太弱，仅从减速壳层中的离心浮力缺失也可以产生同样大的应力。 之前对此效应的分析基于一种简单的描述方式，即假设存在两种（壳层和中子超流体）成分，并且它们被认为是动态独立的。 然而，最近的研究表明，更现实的做法是假定这些成分之间会通过强烈的（非耗散性）嵌入效应相互耦合，而本文的调查正是针对这一效应的后果展开的。 本文显示，考虑到这种嵌入效应会降低估计的角速度差异值，从而需要上调参与观测到的脉冲星glitches（频率突变）的超流体的转动惯量估计值。 然而，嵌入效应并未显著影响之前的结论，即由离心浮力缺失产生的应力在大小上可能与钉扎效应产生的应力相当（尽管方向相反）。 由此得出的推论是，glitches（频率突变）现象能够在非常普遍的情况下发生，这一点可以从异常X射线脉冲星中大型glitches（频率突变）的最新观测结果中得到印证。 显示英文摘要

摘要： The build up of the stress whose relaxation is presumed to account for pulsar frequency glitches can be attributed to various mechanisms, of which the most efficient involve differential rotation of the neutron superfluid in the inner layers of the (magnetically braked) solid crust of a rotating neutron star. In such a case it is usually supposed that the stress is attributable to pinning of superfluid vortices to crust nuclei. It was however suggested a few years ago that, even if the pinning effect is too weak, a comparably large stress can still arise just from the deficit of centrifugal buoyancy in the slowed down crust. The previous analysis of this effect was based on a simple description in terms of two (crustal and neutron superfluid) constituents that were supposed to be dynamically independent. However it has recently been shown that it is more realistic to suppose that the constituents will be mutually coupled by a strong (non dissipative) entrainment effect, whose consequences are the subject of the present investigation. It is shown here that allowance for this entrainment reduces the estimated values of the angular velocity differences, thus requiring upward revision of estimated moment of inertia of superfluid involved in observed pulsar gliches. However the entrainment does not substantially affect the previous conclusion that stresses due to a centrifugal buoyancy deficit can be comparable in magnitude (though opposite in sign) to those produced by pinning. An implication is that the glitch phenomenon will be able to occur under very general circumstances, as witnessed by recent observations of large glitches in anomalous X ray pulsars