arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0710.4986astro-ph
收藏

磁化中子星的轴对称环形模

Axisymmetric toroidal modes of magnetized neutron stars

U. Lee

摘要:

我们计算了具有固体壳的磁化中子星的轴对称环形模。我们假设恒星内部有一个极向磁场穿过,该磁场在表面与外部偶极场连续,其在磁极处的强度为$B_p$ G。由于分离的变量是不可能的磁化星的振荡,我们采用有限的级数展开的扰动使用球谐函数来表示的角度依赖的振荡模式。对于$B_p\sim 10^{16}$ G,我们发现不同的模式序列,在每一个环形模式的振荡频率缓慢增加的径向节点的本征函数的数目增加。$B_p\sim 10^{16}$ G的环形模的频谱与非磁化模型的地壳环形模的频谱有很大的不同,尽管频率范围彼此重叠。这表明,如果恒星的磁场强度与$B_p\sim 10^{16}$ G一样强,那么基于磁环模式对观测到的QPO进行解释是可能的。

英文摘要:

We calculate axisymmetric toroidal modes of magnetized neutron stars with a solid crust. We assume the interior of the star is threaded by a poloidal magnetic field that is continuous at the surface with the outside dipole field whose strength $B_p$ at the magnetic pole is $B_p\sim 10^{16}$G. Since separation of variables is not possible for oscillations of magnetized stars, we employ finite series expansions of the perturbations using spherical harmonic functions to represent the angular dependence of the oscillation modes. For $B_p\sim 10^{16}$G, we find distinct mode sequences, in each of which the oscillation frequency of the toroidal mode slowly increases as the number of radial nodes of the eigenfunction increases. The frequency spectrum of the toroidal modes for $B_p\sim 10^{16}$G is largely different from that of the crustal toroidal modes of the non-magnetized model, although the frequency ranges are overlapped each other. This suggests that an interpretation of the observed QPOs based on the magnetic toroidal modes may be possible if the field strength of the star is as strong as $B_p\sim 10^{16}$G.

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。

↑