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arXiv 0801.1147astro-ph
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脉冲星外磁层间隙中粒子加速和非热辐射

Particle Acceleration and Non-Thermal Emission in Pulsar Outer Magnetospheric Gap

J. Takata, H. -K. Chang, S. Shibata

摘要:

利用二维电动力学模型研究了脉冲星磁层中粒子的加速和非热辐射机制。我们求解了发射过程和电子对产生过程的加速电场在包括旋转轴和磁轴在内的子午平面上的分布。通过求解洛伦兹因子和俯仰角的演化,我们计算了在曲率辐射、同步辐射和逆康普顿过程下,通过$γ$射线带的出射粒子和入射粒子的光谱,这些在以前的研究中被忽略了。我们将这一理论应用于船帆座脉冲星。我们发现,曲率辐射的出射粒子是主要的发射过程以上的10 MeV带。在从软$γ$射线到硬X射线的波段中,来自间隙中进入的初级粒子的同步辐射在光谱中占主导地位。在硬X射线波段以下,来自传出和传入粒子的同步辐射对计算的光谱都有贡献。计算的谱与观测到的Vela脉冲星的相位平均谱是一致的。结果表明,Vela脉冲星X射线波段的五峰脉冲轮廓可以由向内和向外辐射再现,而$γ$射线波段的双峰脉冲轮廓可以由向外辐射解释。

英文摘要:

A two-dimensional electrodynamic model is used to study particle acceleration and non-thermal emission mechanisms in the pulsar magnetospheres. We solve distribution of the accelerating electric field with the emission process and the pair-creation process in meridional plane, which includes the rotational axis and the magnetic axis. By solving the evolutions of the Lorentz factor, and of the pitch angle, we calculate spectrum in optical through $γ$-ray bands with the curvature radiation, synchrotron radiation, and inverse-Compton process not only for outgoing particles, but also for ingoing particles, which were ignored in previous studies. We apply the theory to the Vela pulsar. We find that the curvature radiation from the outgoing particles is the major emission process above 10 MeV bands. In soft $γ$-ray to hard X-ray bands, the synchrotron radiation from the ingoing primary particles in the gap dominates in the spectrum. Below hard X-ray bands, the synchrotron emissions from both outgoing and ingoing particles contribute to the calculated spectrum. The calculated spectrum is consistent with the observed phase-averaged spectrum of the Vela pulsar. We show that the observed five-peak pulse profile in the X-ray bands of the Vela pulsar is reproduced by the inward and outward emissions, and the observed double-peak pulse profile in $γ$-ray bands is explained by the outward emissions.

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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