arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1108.1600astro-ph.HE
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轴对称脉冲星磁层的粒子模拟:II。偶极场情形

A Particle Simulation for the Axisymmetric Pulsar Magnetosphere: II. the case of dipole field

Tomohide Wada, Shinpei Shibata

摘要:

脉冲星磁层的主要问题是旋转能量如何转换成粒子束,导致脉冲发射,以及形成周围星云的电子-正电子等离子体的高度相对论风,在X射线和TeV伽马射线中闪耀。作为第一篇论文(Wada & Shibata 2007)的续篇,我们对轴对称的全球磁层进行了三维粒子模拟。我们给出了额外的计算结果,这是更高的分辨率模型和更高的对创建率的情况下,并详细分析的解决方案。我们仅限于展示低对创建率的情况,即,磁场为固定偶极子。等离子体的辐射阻力取曲率半径沿偶极磁场的形式。通过可编程专用计算机GRAPE-DR计算静电相互作用(Makino et al 2007)。一旦在外部间隙中开始产生对,由于辐射阻力,两个带符号的粒子开始漂移穿过闭合磁场,并且它们产生流出。最后,稳定的磁层有外部的差距,都签署外流的等离子体和一个区域,其中电场是占主导地位的延伸从赤道。在稳定状态下,磁层电流产生的磁场与恒星几个光半径以外的偶极磁场相当。在更高的电子对产生率模型中,磁场的改变会导致等离子体流出量的改变,需要在后续的论文中进一步研究更高的电子对产生率模型。

英文摘要:

The main issue of the pulsar magnetosphere is how the rotation power is converted into both particle beams which causes pulsed emissions, and a highly relativistic wind of electron-positron plasmas which forms surrounding nebulae shining in X-rays and TeV gamma-rays. As a sequel of the first paper (Wada & Shibata 2007), we carried out a three dimensional particle simulation for the axisymmetric global magnetosphere. We present the results of additional calculations, which are higher resolution model and higher pair creation rate cases, and a detailed analysis for the solution. We confined to demonstrate the cases of low pair creation rate, i.e., the magnetic field is fixed dipole. The radiation drag of the plasma is taken in a form with the curvature radius along the dipole magnetic field. The electrostatic interactions are calculated by a programmable special purpose computer, GRAPE-DR (Makino et al 2007). Once pair creation is onset in the outer gaps, the both signed particles begin to drift across the closed magnetic field due to radiation drag, and they create outflow. Eventually, the steady magnetosphere has outer gaps, both signed outflow of plasma and a region in which the electric field is dominant extending from the equator. In the steady state, the magnetic field made by magnetospheric current is comparable to the dipole magnetic field outside of several light radii from the star. In much more pair creation rate model, the effect of modification of the magnetic field will bring about modification of the outflow of the plasma, requiring further study with higher pair creation rate model in a subsequent paper.

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。

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