论文标题
弹性应变朝着磁性中子恒星中的地壳裂缝的积累
Accumulation of elastic strain toward crustal fracture in magnetized neutron stars
论文作者
论文摘要
这项研究调查了由大厅漂移驱动的弹性变形，中子磁性的中子地壳。尽管动态平衡最初是没有弹性位移而保持的，但磁场的演变会在世俗的时间尺度上改变洛伦兹力，这不可避免地会导致弹性变形在新的力平衡中沉降。因此，积累了弹性能，最终将外壳骨折超出了特定阈值。我们假设磁场在轴向对称性上是对称的，我们明确计算了分解时间，储存在地壳中的最大弹性能以及空间剪切压力分布。对于在没有环形场的内部芯上排出的多型偶极场的正压平衡，分解时间对应于磁场强度为$ \ sim 10^{15} $ g的磁场的几年；但是，对于普通无线电脉冲星，它超过了1 MYR。裂缝之前存储在地壳中的弹性能量范围从$ 10^{41} $到$ 10^{45} $ ERG，具体取决于空间 - 能量分布。通常，大量能量沉积在深层地壳中。当弹性位移的重排仅出现在脆弱的浅层外壳中时，在骨折上释放的能量通常为$ \ sim 10^{41} $ erg。能量的量与磁铁上的爆发能量相当。
This study investigates elastic deformation driven by the Hall drift in a magnetized neutron-star crust. Although the dynamic equilibrium initially holds without elastic displacement, the magnetic-field evolution changes the Lorentz force over a secular timescale, which inevitably causes the elastic deformation to settle in a new force balance. Accordingly, elastic energy is accumulated, and the crust is eventually fractured beyond a particular threshold. We assume that the magnetic field is axially symmetric, and we explicitly calculate the breakup time, maximum elastic energy stored in the crust, and spatial shear-stress distribution. For the barotropic equilibrium of a poloidal dipole field expelled from the interior core without a toroidal field, the breakup time corresponds to a few years for the magnetars with a magnetic field strength of $\sim 10^{15}$G; however, it exceeds 1 Myr for normal radio pulsars. The elastic energy stored in the crust before the fracture ranges from $10^{41}$ to $10^{45}$ erg, depending on the spatial-energy distribution. Generally, a large amount of energy is deposited in a deep crust. The energy released at fracture is typically $\sim 10^{41}$ erg when the rearrangement of elastic displacements occurs only in the fragile shallow crust. The amount of energy is comparable to the outburst energy on the magnetars.
