论文标题
FRB衰减的相干发射
FRB Coherent Emission from Decay of Alfven Waves
论文作者
论文摘要
我们提出了一个模型的FRB模型，其中大幅度Alfven波数据包由磁铁表面附近的干扰发射，并且波浪能的很大一部分被转换为相干的无线电波，在几十个中子星形半径的距离处。为了产生各向同性的光度10 $^{44} $ erg s $^{ - 1} $，磁表面的波幅度应约为1011克。沿静态磁场的电流由具有横向波形的非零分量的Alfven波需要。电流是通过反向流的电子 - 词素对提供的，随着等离子体密度随着距磁场表面的距离而降低，必须以较大半径的光速移动。反向流对受到两流不稳定性的约束，这会导致形成顺序$ c/ω_p$的粒子束；其中$ω_p$是等离子体频率。当波数据包到达半径时，强烈的电场会沿静态磁场发展，在该半径上，在该半径上，电子 - 峰值密度不足以提供波浪所需的电流。电场沿弯曲的磁场线加速粒子，并产生连贯的FRB辐射。我们提供了该模型的许多预测。
We present a model for FRBs where a large amplitude Alfven wave packet is launched by a disturbance near the surface of a magnetar, and a substantial fraction of the wave energy is converted to coherent radio waves at a distance of a few tens of neutron star radii. The wave amplitude at the magnetar surface should be about 1011G in order to produce a FRB of isotropic luminosity 10$^{44}$ erg s$^{-1}$. An electric current along the static magnetic field is required by Alfven waves with nonzero component of transverse wave-vector. The current is supplied by counter-streaming electron-positron pairs, which have to move at nearly the speed of light at larger radii as the plasma density decreases with distance from the magnetar surface. The counter-streaming pairs are subject to two-stream instability which leads to the formation of particle bunches of size of order $c/ω_p$; where $ω_p$ is plasma frequency. A strong electric field develops along the static magnetic field when the wave packet arrives at a radius where electron-positron density is insufficient to supply the current required by the wave. The electric field accelerates particle bunches along the curved magnetic field lines, and that produces the coherent FRB radiation. We provide a number of predictions of this model.
