发表机构
Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences; Department of Physics, University of Milan; INFN, Sezione di Milano; Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena（波兰科学院尼古拉·哥白尼天文学中心; 米兰大学物理系; 意大利国家核物理研究所米兰分部; 耶拿弗里德里希·席勒大学理论物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过三维广义相对论磁流体模拟，发现中子星内部磁场结构由旋转状态决定：快速旋转形成强环向场（如射电脉冲星），磁主导则保留极向场（如磁星），统一解释了中子星类别多样性。
AI 中文摘要
磁场是中子星物理的基础，并在驱动磁星的极端现象（包括软伽马重复暴和反常X射线脉冲星）中发挥核心作用。然而，其内部磁场的结构和稳定性在很大程度上仍不受约束，因为它们无法通过电磁观测直接探测。利用三维广义相对论磁流体动力学模拟，覆盖一系列旋转速率和磁场强度，我们识别出两种不同的演化机制，它们导向动态稳定的磁结构。在快速旋转的恒星中，阿尔芬穿越时标超过旋转周期，使得差动缠绕能够在不稳定性爆发前放大强环向磁分量，从而产生长寿命的稳定结构。相反，在磁主导的恒星中，极向场的不稳定性驱动快速磁场衰减，仅留下相对较弱的环向分量。这些结果意味着中子星的内部磁结构敏感地依赖于其旋转状态：旋转主导的恒星（如射电脉冲星）发展出强环向磁场，而磁星则以极向构型为主。因此，我们的发现表明，中子星的旋转历史塑造了其内部磁结构，提供了一个统一的物理图景，将观测到的中子星类别多样性与其隐藏的场构型联系起来。
英文摘要
Magnetic fields are fundamental for neutron star physics and play a central role in powering the extreme phenomenology of magnetars, including Soft Gamma Repeaters and Anomalous X-ray Pulsars. However, the structure and stability of their internal magnetic fields remain largely unconstrained, as they cannot be directly probed by electromagnetic observations. Using 3D general-relativistic magnetohydrodynamics simulations across a range of rotation rates and magnetic field strengths, we identify two distinct evolutionary regimes leading towards dynamically stable magnetic configurations. In rapidly rotating stars, the Alfvén crossing timescale exceeds the rotation period, allowing differential winding to amplify a strong toroidal magnetic component before the onset of instabilities, leading to long-lived, stable configurations. In contrast, in magnetically dominated stars, instabilities in the poloidal field drive rapid field decay, leaving only a comparatively weak toroidal component. These results imply that the internal magnetic structure of neutron stars depends sensitively on their rotational state: rotation-dominated stars like radio pulsars develop strong toroidal fields, while magnetars are characterized by predominantly poloidal configurations. Our findings therefore show that a neutron star's rotational history shapes its internal magnetic structure, providing a unifying physical picture that connects the observed diversity of neutron star classes to their hidden field configurations.
Comments12 Pages, 6 Figures
