On the origin and composition of Galactic cosmic rays
On the origin and composition of Galactic cosmic rays
复制标题
银河宇宙线的起源和成分
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
N. Prantzos
中科院分区：
文献类型：
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作者：
N. Prantzos
上下文银河宇宙线（GCR）的组成与标准（宇宙）组成非常相似，但也有明显的差异，其中最重要的是22 Ne/ 20 Ne的高同位素比率，GCR中的22 Ne/ 20 Ne比太阳中的高2.5倍。这一比率提供了关于大湖区起源的关键信息。目标。我们调查的想法，GCR是由超新星爆炸的前向冲击加速，而他们通过大质量恒星的前超新星风和星际介质运行。方法.我们使用详细的风和核心收益率的旋转和非旋转模型的大质量恒星的质量损失，以及简单的模型的属性的前向冲击和星周介质。结果我们发现，如果GCR仅在Sedov相早期加速，则可以解释观察到的GCR 22 Ne/ 20 Ne比，激波速度>1600 km s −1。加速效率约为10 −6 - 10 −5，也就是说，在GCR能量下，激波遇到的百万个粒子中只有少数粒子逃离了SN。我们还定量地表明，广泛宣传的想法，GCR加速超气泡未能占高22 Ne/ 20 Ne比GCR。
Context. The composition of Galactic cosmic rays (GCR) presents strong similarities to the standard (cosmic) composition, but also noticeable differences, the most important of which is the high isotopic ratio of 22 Ne/ 20 Ne, which is ∼5 times higher in GCR than in the Sun. This ratio provides key information on the GCR origin. Aims. We investigate the idea that GCR are accelerated by the forward shocks of supernova explosions, while they run through the pre-supernova winds of the massive stars and through the interstellar medium. Methods. We use detailed wind and core yields of rotating and non-rotating models of massive stars with mass loss, as well as simple models for the properties of the forward shock and of the circumstellar medium. Results. We find that the observed GCR 22 Ne/ 20 Ne ratio can be explained if GCR are accelerated only during the early Sedov phase, for shock velocities >1600 km s −1 . The acceleration efficiency is found to be of the order of 10 −6 –10 −5 , i.e. a few particles out of a million encountered by the shock escape the SN at GCR energies. We also show quantitatively that the widely publicized idea that GCR are accelerated in superbubbles fails to account for the high 22 Ne/ 20 Ne ratio in GCR.