发表机构
University of KwaZulu-Natal（夸祖鲁-纳塔尔大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过欧姆衰变模拟，发现中子星磁场衰减取决于磁通锚定深度：深层磁场可稳定超过百亿年，而浅层磁场快速演化，解释了高龄高磁场脉冲星缺失现象。
AI 中文摘要
中子星壳层磁场通过欧姆衰变进行的长期演化受壳层输运性质的控制。在本工作中，我们证明了磁通量锚定所处的深度在耗散时标中起着重要作用。我们在弯曲时空中的欧姆扩散假设下，研究了由壳层磁场演化引起的中子星表面磁场的演化。我们采用累积分布函数来参数化初始电流分布，并探讨了改变物态方程和壳层杂质的影响。我们比较了代表不同致密程度的中子星模型的三种结果。我们发现，锚定在内壳层更深处的磁场在长达$10^{10}$年的时间尺度上经历可忽略的衰减。如果磁流被限制在浅层外壳中，则可能发生显著的场演化，这对于解释高龄高磁场脉冲星的缺失是必要的。无论杂质浓度或由物态方程决定的壳层具体几何厚度如何，这一结果均成立。
英文摘要
The long-term evolution of neutron star crustal magnetic fields through Ohmic decay is governed by the transport properties of the crust. In this work, we demonstrate that the depth at which the magnetic flux is anchored plays a significant role in the dissipation timescale. We study the evolution of the magnetic field at the surface of the neutron star due to the crustal field evolution, under the assumption of Ohmic diffusion in a curved spacetime. We employ a cumulative distribution function to parameterise the initial current distribution and explore the effects of varying the equation of state and crustal impurity. We compare results across three neutron star models representing varying degrees of compactness. We find that magnetic fields anchored deeper within the inner crust experience negligible decay over timescales up to $10^{10}$ years. Significant field evolution, necessary to explain the deficit of high-field pulsars at advanced ages, is possible if the magnetic currents are confined to the shallow outer crust. This result holds true regardless of the impurity concentration or the specific geometric thickness of the crust determined by the equation of state.
Comments9 pages, 13 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS)
