A new code for the Hall-driven magnetic evolution of neutron stars
A new code for the Hall-driven magnetic evolution of neutron stars
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DOI：
10.1016/j.cpc.2012.04.029
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发表时间：
2012-04
期刊：
影响因子：
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通讯作者：
D. Viganò;J. Pons;J. Miralles
中科院分区：
文献类型：
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作者：
D. Viganò;J. Pons;J. Miralles
近十年来，天体物理中磁场演化的数值模拟已成为一个日益重要的研究领域。在中子星的结晶壳中，磁场的演化受霍尔感应方程控制。在该方程中，两项（霍尔项和欧姆耗散）的相对贡献取决于温度和磁场强度的局部条件。这导致从纯粹的抛物线字符的方程的双曲制度的磁雷诺数的增加，这提出了严重的数值问题的过渡。到目前为止，大多数研究这个问题的尝试都是基于谱方法，但他们未能代表过渡到大磁雷诺数。我们提出了一个新的代码基于迎风有限差分技术，可以处理任意低磁扩散率的情况下，它是适合于研究尖锐的电流片的形成过程中的演变。该程序在不同的极限下进行了全面的测试，并用于说明中子星星中地壳磁场在一些典型情况下的演化。我们的代码，再加上冷却代码，可以用来执行长期的模拟中子星的磁热演化。
Over the past decade, the numerical modeling of the magnetic field evolution in astrophysical scenarios has become an increasingly important field. In the crystallized crust of neutron stars the evolution of the magnetic field is governed by the Hall induction equation. In this equation the relative contribution of the two terms (Hall term and Ohmic dissipation) varies depending on the local conditions of temperature and magnetic field strength. This results in the transition from the purely parabolic character of the equations to the hyperbolic regime as the magnetic Reynolds number increases, which presents severe numerical problems. Up to now, most attempts to study this problem were based on spectral methods, but they failed in representing the transition to large magnetic Reynolds numbers. We present a new code based on upwind finite differences techniques that can handle situations with arbitrary low magnetic diffusivity and it is suitable for studying the formation of sharp current sheets during the evolution. The code is thoroughly tested in different limits and used to illustrate the evolution of the crustal magnetic field in a neutron star in some representative cases. Our code, coupled to cooling codes, can be used to perform long-term simulations of the magneto-thermal evolution of neutron stars.