论文标题
旋转恒星周围环境中真空电磁场的一般解决方案
General solution for the vacuum electromagnetic field in the surroundings of a rotating star
论文作者
论文摘要
目标。许多最近对脉冲星和磁铁的观察结果可以用多极电磁场的中子星（NS）来解释。作为第一个近似值，当这种环境被剥夺了等离子体时，我们研究了旋转恒星环境中的多极磁场和电场。方法。我们计算真空中电磁场的多极膨胀，以在旋转恒星的导电表面上给定的磁场。然后，我们考虑了脉冲星的多极场的一些后果。结果。我们提供解决方案的明确形式。对于磁场的每个球形谐波，扩展包含有限数量的项。多极磁场可以为脉冲的稳定亚结构提供解释，并为脉冲星磁层中电流闭合问题提供了解决方案。结论。该计算概括了用偶极场真空中旋转星的广泛使用的模型。它可以作为与紧凑型恒星的电磁环境的第一个近似，例如具有任意磁场的中子恒星。
Aims. Many recent observations of pulsars and magnetars can be interpreted in terms of neutron stars (NS) with multipole electromagnetic fields. As a first approximation, we investigate the multipole magnetic and electric fields in the environment of a rotating star when this environment is deprived of plasma. Methods. We compute a multipole expansion of the electromagnetic field in vacuum for a given magnetic field on the conducting surface of the rotating star. Then, we consider a few consequences of multipole fields of pulsars. Results. We provide an explicit form of the solution. For each spherical harmonic of the magnetic field, the expansion contains a finite number of terms. A multipole magnetic field can provide an explanation for the stable sub-structures of pulses, and they offer a solution to the problem of current closure in pulsar magnetospheres. Conclusions. This computation generalises the widely used model of a rotating star in vacuum with a dipole field. It can be especially useful as a first approximation to the electromagnetic environment of a compact star, for instance a neutron star, with an arbitrarily magnetic field.
