论文标题
时间依赖性的粒子加速度和发射模型：了解粒子光谱演化和大耀斑
A time-dependent particle acceleration and emission model: Understanding the particle spectral evolution and blazar flares
论文作者
论文摘要
Blazars的喷射以其多波长的耀斑和快速的极端变化而闻名。但是，关于负责这些频谱和时间变化的物理过程，仍然存在一些重要的未解决问题。在本文中，我们开发了一个时间依赖性的粒子演化模型，以用于大黄蜂的时变发射光谱。在模型中，我们引入了时间依赖性的电场和磁场，其中始终包括传输方程中相关物理量的变异性。 The evolution on the electron distribution is numerically solved from a generalized transport equation that contains the terms describing the electrostatic, first-order and second-order \emph{Fermi} acceleration, escape of particles due to both advection and spatial diffusion, as well as energy losses due to the synchrotron emission and inverse-Compton scattering of both synchrotron and external ambient photon fields.我们发现，大部分的光曲线曲线与时间依赖的电场和磁场产生的颗粒光谱演化是一致的，而不是加速度或冷却过程的效果。所提出的模型能够同时说明能量光谱和BL LAC对象MRK 421的光曲线曲线的可变性，并具有对物理参数的合理假设。结果强烈表明，大射流的消散区域中的磁场演变可以解释变异性。
The jets of blazars are renowned for their multi-wavelength flares and rapid extreme variability; however, there are still some important unanswered questions about the physical processes responsible for these spectral and temporal changes in emission properties. In this paper, we develop a time-dependent particle evolution model for the time-varying emission spectrum of blazars. In the model, we introduce time-dependent electric and magnetic fields, which consistently include the variability of relevant physical quantities in the transport equation. The evolution on the electron distribution is numerically solved from a generalized transport equation that contains the terms describing the electrostatic, first-order and second-order \emph{Fermi} acceleration, escape of particles due to both advection and spatial diffusion, as well as energy losses due to the synchrotron emission and inverse-Compton scattering of both synchrotron and external ambient photon fields. We find that the light curve profiles of blazars are consistent with the particle spectral evolution resulting from time-dependent electric and magnetic fields, rather than the effects of the acceleration or the cooling processes. The proposed model is able to simultaneously account for the variability of both the energy spectrum and the light curve profile of the BL Lac object Mrk 421 with reasonable assumptions about the physical parameters. The results strongly indicate that the magnetic field evolution in the dissipated region of a blazar jet can account for the variabilities.
