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arXiv 1303.3404astro-ph.HE
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旋转驱动Gamma-ray脉冲星的亮度演化

Luminosity Evolution of Rotation-powered Gamma-ray Pulsars

Kouichi Hirotani

摘要:

本文研究了脉冲星外磁层粒子加速器的电动力学结构及其产生的γ射线辐射。通过考虑加速器自持的条件,推导出加速器跨磁场厚度随脉冲星年龄的变化规律。结果表明,当中子星包层被足够的轻元素污染时,包层的厚度很小,但会稳定地增加。对于这样一个轻元素包层,加速器的伽马射线光度在最初的一万年中作为年龄的函数保持近似恒定,形成了观测到的旋转驱动的恒星的伽马射线光度分布的下限。另一方面,如果包层仅由重元素组成,则厚度比轻元素包层的厚度大,但增加得慢。对于这样一个重元素包层,伽马射线光度相对快速地下降,形成了观测到的分布的上限。一般脉冲星的伽马射线光度介于这两种极端情况之间,反映了包络成分和相对于旋转轴的磁倾角。

英文摘要:

We investigate the electrodynamic structure of a pulsar outer-magnetospheric particle accelerator and the resultant gamma-ray emission. By considering the condition for the accelerator to be self-sustained, we derive how the trans-magnetic-field thickness of the accelerator evolves with the pulsar age. It is found that the thickness is small but increases steadily if the neutron-star envelope is contaminated by sufficient light elements. For such a light element envelope, the gamma-ray luminosity of the accelerator is kept approximately constant as a function of age in the initial ten thousand years, forming the lower bound of the observed distribution of the gamma-ray luminosity of rotation-powered pulsars. If the envelope consists of only heavy elements, on the other hand, the thickness is greater but increases less rapidly than what a light element envelope has. For such a heavy element envelope, the gamma-ray luminosity decreases relatively rapidly, forming the upper bound of the observed distribution. The gamma-ray luminosity of a general pulsar resides between these two extreme cases, reflecting the envelope composition and the magnetic inclination angle with respect to the rotation axis.

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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