非正压星磁场的稳定性：一种解析处理
Stability of magnetic fields in non-barotropic stars: an analytic treatment
摘要：
我们知道，在主序星、白矮星和中子星中，磁场的持续时间与它们的寿命相当。从理论的角度来看，这是有问题的，因为可以表明，简单的磁场配置总是不稳定的。在非正压恒星中，稳定的层结允许比正压恒星更广泛的磁场结构，并通过使其更难引起径向位移来帮助稳定它们。布雷斯韦特及其合作者最近的模拟表明，在稳定分层的恒星中，随机初始磁场演变为具有极向分量和环向分量的近轴对称配置，然后在一段时间内保持稳定。这是可取的，提供一个分析研究的稳定性，这样的领域。我们写一个合理的平衡结构的轴对称磁场的极向和环向分量的强度可调，在一个非正压静态流体星的显式表达式，并研究其稳定性使用的能量原理。我们构建了一个位移场，应该是一个合理的近似最不稳定的模式的环向场，并确认Braithwaite的结果，一个给定的环向场可以稳定的极向场包含比前者少得多的能量。这与环向场是驱动磁星活动的主要储层的推测是一致的。由隐藏的环向场引起的中子星的变形也可以引起引力波的发射。
英文摘要：
Magnetic fields in upper main-sequence stars, white dwarfs, and neutron stars are known to persist for timescales comparable to their lifetimes. From a theoretical perspective this is problematic, as it can be shown that simple magnetic field configurations are always unstable. In non-barotropic stars, stable stratification allows for a much wider range of magnetic field structures than in barotropic stars, and helps stabilize them by making it harder to induce radial displacements. Recent simulations by Braithwaite and collaborators have shown that, in stably stratified stars, random initial magnetic fields evolve into nearly axisymmetric configurations with both poloidal and toroidal components, which then remain stable for some time. It is desirable to provide an analytic study of the stability of such fields. We write an explicit expression for a plausible equilibrium structure of an axially symmetric magnetic field with both poloidal and toroidal components of adjustable strengths, in a non-barotropic static fluid star, and study its stability using the energy principle. We construct a displacement field that should be a reasonable approximation to the most unstable mode of a toroidal field, and confirm Braithwaite's result that a given toroidal field can be stabilized by a poloidal field containing much less energy than the former. This is consistent with the speculation that the toroidal field is the main reservoir powering magnetar activity. The deformation of a neutron star caused by the hidden toroidal field can also cause emission of gravitational waves.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
