Abstract

In pulsating X-ray sources a magnetized neutron star is surrounded by an accretion disk whose structure requires a study. In particular, the dipole magnetic field of the star can partially penetrate the disk and, freezing into the matter, can give rise to an induced magnetic field in the disk. The field growth can be limited by its turbulent diffusion. In this paper we calculate such an induced field. The problem is reduced to solving the induction equation in the presence of diffusion. An analytical solution of the equation has been obtained, with the radial and vertical structures of the induced field having been calculated simultaneously. The radial structure is close to the previously predicted dependence on the difference of the angular velocities of the disk and the magnetosphere: \(b\propto\Omega_{\textrm{s}}-\Omega_{\textrm{k}}\), while the vertical structure of the field is close to the linear proportionality between the field and the height above the equator: \(b\propto z\). The possibility of the existence of nonstationary quasi-periodic components of the induced magnetic field is discussed.

中文翻译：

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中子星周围吸积盘中的感应磁场

摘要

在脉动 X 射线源中，磁化中子星被吸积盘包围，吸积盘的结构需要研究。特别是，恒星的偶极子磁场可以部分穿透圆盘，并冻结到物质中，可以在圆盘中产生感应磁场。场的增长可能会受到其湍流扩散的限制。在本文中，我们计算了这样的感应场。该问题简化为求解存在扩散的情况下的归纳方程。得到了方程的解析解，同时计算了感应场的径向和垂直结构。径向结构接近于先前预测的对盘和磁层角速度差的依赖关系：\(b\propto\Omega_{\textrm{s}}-\Omega_{\textrm{k}}\)，而场的垂直结构接近于场与赤道上方高度之间的线性比例：\(b\propto z\)。讨论了感应磁场中非平稳准周期分量存在的可能性。