arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1909.01699astro-ph.HE
收藏

双偶极子模型在具有反常制动指数的脉冲星PSR J1640-4631中的应用

Application of a two dipole model to PSR J1640-4631, a pulsar with an anomalous braking index

Hui Shi, Hong-Wei Hu, Wen-Cong Chen

摘要:

最近的定时观测提供了一个有趣的结果,X射线脉冲星PSR J 1640 -4631的制动指数,它有一个测量的制动指数$n=3.15\pm0.03$。自旋轴和磁轴之间的倾斜角的减小可能是这种高制动指数的原因。然而,引起磁倾角变化的物理机制尚未完全了解。在这封信中,我们应用Hamil等人(2016)给出的双偶极子模型来解释PSR J1640-4631的磁倾角减小。带电球体的旋转效应和铁磁有序材料的磁化分别产生磁矩$M_{1}$和$M_{2}$。在$M_{1}$的磁场中存在磁矩$M_{2}$的势能的最小值,因此$M_{2}$将围绕最小能量位置(即,$M_{2}$)自由旋转。e平衡位置),类似于单摆。计算结果表明,PSR J1640-4631的磁矩$M_{2}$将向与自旋轴一致的方向演化,并导致磁倾角减小。脉冲轮廓中的单峰有利于磁倾角的相对低的变化率。

英文摘要:

Recent timing observation provides an intriguing result for the braking index of the X-ray pulsar PSR J1640-4631, which has a measured braking index $n=3.15\pm0.03$. The decrease of the inclination angle between between the spin axis and the magnetic axis can be responsible for such a high braking index. However, the physical mechanisms causing the change of the magnetic inclination angle have not been fully understood. In this Letter, we apply a two-dipole model given by Hamil et al (2016) to explain the decrease of the magnetic inclination angle of PSR J1640-4631. The rotation effect of a charged sphere and the magnetization of ferromagnetically ordered material produce magnetic moments $M_{1}$ and $M_{2}$, respectively. There exist a minimum of the potential energy for the magnetic moment $M_{2}$ in the magnetic field of $M_{1}$, hence the $M_{2}$ will freely rotate around the minimum energy position (i. e equilibrium position), similar to a simple pendulum. Our calculation indicate the magnetic moment $M_{2}$ would evolve towards alignment with the spin axis for PSR J1640-4631, and cause the magnetic inclination angle to decrease. The single peak in the pulse profile favors a relatively low change rate of the magnetic inclination angle.

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。

↑