论文标题
FERMI加速机制之间的相互作用的数值研究
A numerical study of the interplay between Fermi acceleration mechanisms in radio lobes of FR-II radio galaxies
论文作者
论文摘要
上下文:被视线大通的AGN被认为具有各种粒子加速度的位点,这导致观察到的非热光谱。在弱磁化环境中,随机湍流加速度(STA)和扩散冲击加速度(DSA)通常被称为高能颗粒的潜在来源。这些加速过程和各种辐射损失共同决定了这些半乳酸无线电来源的发射特性。 目的:这项研究的目的是研究FR-II射电星系无线电裂片中的STA和DSA之间的动态相互作用,以及这些加速机制以及各种辐射损失的方式,共同塑造了这些速率外来中所见的发射特征。 方法:通过一种新型混合欧拉格兰 - 拉格朗日框架,考虑了一种以现象学动机的STA模型,然后在磁流动力模拟的无线电叶上使用。 结果:STA产生弯曲的粒子光谱,在形态上与通常的冲击加速光谱不同。由于基础粒子能谱的这种结构差异,各种多波长特征在无线电叶的光谱能量分布中出现。此外,我们观察到除了DSA外,还考虑了STA的情况下,无线电裂片从无线电裂片发出了增强的X射线发射。
Context: Radio-loud AGNs are thought to possess various sites of particle acceleration, which gives rise to the observed non-thermal spectra. Stochastic turbulent acceleration (STA) and diffusive shock acceleration (DSA) are commonly cited as potential sources of high-energy particles in weakly magnetized environments. Together, these acceleration processes and various radiative losses determine the emission characteristics of these extra-galactic radio sources. Aims: The purpose of this research is to investigate the dynamical interplay between the STA and DSA in the radio lobes of FR-II radio galaxies, as well as the manner in which these acceleration mechanisms, along with a variety of radiative losses, collectively shape the emission features seen in these extra-galactic sources. Methods: A phenomenologically motivated model of STA is considered and subsequently employed on a magneto-hydrodynamically simulated radio lobe through a novel hybrid Eulerian-Lagrangian framework. Results: STA gives rise to a curved particle spectrum that is morphologically different from the usual shock-accelerated spectrum. As a consequence of this structural difference in the underlying particle energy spectrum, various multi-wavelength features arise in the spectral energy distribution of the radio lobe. Additionally, we observe enhanced diffuse X-ray emission from radio lobes for cases where STA is taken into account in addition to DSA.