论文标题
来自MHD模拟的中子星中的磁场配置
Magnetic field configurations in neutron stars from MHD simulations
论文作者
论文摘要
我们通过使用代码冥王星进行非线性磁性流体动力学模拟，从数值上研究了正压中子星中磁场的演变。对于最初具有不同强度的主要型球场和环形磁场，我们发现该磁场沉降到混合的螺状螺旋构型，在该构型中，环形组分的总磁能的10％至20％。但是，这并不是严格的平衡，因为不稳定性导致湍流的发展，这又导致了逆螺旋性级联反应，这决定了最终的“扭曲圆环”设置。因此，最终的字段配置是由不稳定性的非线性饱和度决定的，而不是静止的。然而，在我们的模拟中，杆和环形成分的平均能量大致稳定，并且在表面上出现了复杂的多极结构，而磁场在恒星外部的外部边界处是偶极。
We have studied numerically the evolution of magnetic fields in barotropic neutron stars, by performing nonlinear magnetohydrodynamical simulations with the code PLUTO. For both initially predominantly poloidal and toroidal fields, with varying strengths, we find that the field settles down to a mixed poloidal-toroidal configuration, where the toroidal component contributes between 10% and 20% of the total magnetic energy. This is, however, not a strict equilibrium, as the instability leads to the development of turbulence, which in turn gives rise to an inverse helicity cascade, which determines the final 'twisted torus' setup. The final field configuration is thus dictated by the non-linear saturation of the instability and is not stationary. The average energy of the poloidal and toroidal components, however, is approximately stable in our simulations, and a complex multipolar structure emerges at the surface, while the magnetic field is dipolar at the exterior boundary, outside the star.
