论文标题
光子在相对论等离子体中的散射速度剪切：高能量幂律光谱的产生
Photons' scattering in a relativistic plasma with velocity shear: generation of high energy power-law spectra
论文作者
论文摘要
高能能力定律是许多天体物理物体光谱中的共同特征。我们表明，具有可变洛伦兹因子的相对论等离子体中的光子通过电子重复散射以获得能量。逃逸的光子人群自然会产生幂律形状的光谱，使其成为与带电颗粒的常规费米加速机制的各向异性类似物。因此，该机制通过同步加速器或热构造提供了当前对高能幂律光谱的解释的自然替代方法。该模型适用于具有任意Lorentz因子轮廓的任何相对论等离子体束。我们将理论实施到GRB迅速阶段，并表明所获得的光子指数范围与观察到的值兼容。因此，观察到的高能谱指数为射流结构提供了独特的指标。
A high energy power law is a common feature in the spectra of many astrophysical objects. We show that the photons in a relativistic plasma with a variable Lorentz factor go through repeated scattering with electrons to gain energy. The escaped population of photons naturally produces a power-law-shaped spectrum making it an anisotropic analogue to the conventional Fermi acceleration mechanism of charged particles. Thus, this mechanism provides a natural alternative to current explanations of high energy power-law spectra via synchrotron or thermal Comptonization. The model is applicable to any relativistic plasma beam with an arbitrary Lorentz factor profile. We implement the theory to GRB prompt phase and show that the obtained range of the photon indices is compatible with the observed values. Therefore, the observed high energy spectral indices provide a unique indicator of the jet structure.
