Particle Acceleration in Gamma-Ray Burst Jets
Particle Acceleration in Gamma-Ray Burst Jets
复制标题
伽马射线爆射流中的粒子加速
DOI：
10.1086/497634
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
P. Duffy
中科院分区：
文献类型：
--
作者：
F. Rieger;P. Duffy
研究了γ射线暴喷流中高能粒子的剪切加速。特别强调的是通用结构射流的分析，和特征加速时间尺度确定的幂律演化和高斯演化的整体流洛伦兹因子γB与角θ从射流轴。结果表明，当地的幂律粒子分布可能会产生，较高的能量粒子一般集中在更接近射流轴。考虑到几个约束条件，我们表明，有效的电子加速在逐渐剪切流，最大粒子能量随时间连续下降，可能在尺度大于r ~ 1015厘米，提供射流磁场变得足够弱和/或减少足够迅速的距离，而在宽范围的条件下将质子有效加速到>1020 eV的高能是可能的。
The gradual shear acceleration of energetic particles in gamma-ray burst (GRB) jets is considered. Special emphasis is given to the analysis of universal structured jets, and characteristic acceleration timescales are determined for a power-law evolution and a Gaussian evolution of the bulk flow Lorentz factor γb with angle ϕ from the jet axis. The results suggest that local power-law particle distributions may be generated and that higher energy particles are generally concentrated closer to the jet axis. Taking several constraints into account, we show that efficient electron acceleration in gradual shear flows, with maximum particle energy successively decreasing with time, may be possible on scales larger than r ~ 1015 cm, provided the jet magnetic field becomes sufficiently weak and/or decreases rapidly enough with distance, while efficient acceleration of protons to ultrahigh energies >1020 eV may be possible under a wide range of conditions.