论文标题
相对论磁性冲击的同步加速器maser发射：依赖于冲击的温度
The synchrotron maser emission from relativistic magnetized shocks: Dependence on the pre-shock temperature
论文作者
论文摘要
最近，已经调用了由同步磁性磁性冲击物在相对论磁性冲击下产生的电磁前体波，以解释快速无线电爆发的连贯无线电发射。通过二维粒子中的粒子模拟，我们探索了相对论电子 - 峰垂直电击中前体波的特性，这是预动摇磁化$σ\ gtrsim 1 $ 1 $（即，降压剂量与粒子范围的比率）的函数的函数。 kt/mc^2 = 10^{ - 5} -10^{ - 1} $。我们测量将转换为前体波的总传入能量的分数$f_松。在固定磁化时，我们发现$f_ξ$几乎独立于温度独立于温度，只要$Δγ\ lyssim 10^{ - 1.5} $（仅$δγ= 10^{ - 5} $至$δγ= 10^= 10^{ - 1.5} $），但$Δγ= 10^{ - 5} $），但IT下降了几乎两位$Δ 10^{ - 1} $。在固定温度下，具有磁化尺寸的缩放$f_ξ\ sim 10^{ - 3} \，σ^{ - 1} $与我们较早的一维结果一致。对于我们的参考$σ= 1 $，对于寒冷温度，前体波的功率谱相对较宽（分数宽度$ \ sim 1-3 $），而它显示出明显的类似线的特征，具有分数宽度$ \ sim 0.2 $，$ 10^{ - 3} { - 3} \ 3} \ 3} \ 3} \ silysimΔγγγ\ sim fimes sim sim sim 10^^$ 1.5} $ 1.5}。对于$σ\ gtrsim 1 $，从冲击正常（如在后冲击后框架中测量），前体波在角度$ \ simeqσ^{ - 1/2} $的角度上进行束缚，以便它们可以超越冲击。我们的结果可以为基于相对论冲击的maser发射的FRB发射模型提供物理基础的输入。
Electromagnetic precursor waves generated by the synchrotron maser instability at relativistic magnetized shocks have been recently invoked to explain the coherent radio emission of Fast Radio Bursts. By means of two-dimensional particle-in-cell simulations, we explore the properties of the precursor waves in relativistic electron-positron perpendicular shocks as a function of the pre-shock magnetization $σ\gtrsim 1$ (i.e., the ratio of incoming Poynting flux to particle energy flux) and thermal spread $Δγ\equiv kT/mc^2=10^{-5}-10^{-1}$. We measure the fraction $f_ξ$ of total incoming energy that is converted into precursor waves, as computed in the post-shock frame. At fixed magnetization, we find that $f_ξ$ is nearly independent of temperature as long as $Δγ\lesssim 10^{-1.5}$ (with only a modest decrease of a factor of three from $Δγ=10^{-5}$ to $Δγ=10^{-1.5}$), but it drops by nearly two orders of magnitude for $Δγ\gtrsim 10^{-1}$. At fixed temperature, the scaling with magnetization $f_ξ\sim 10^{-3}\,σ^{-1}$ is consistent with our earlier one-dimensional results. For our reference $σ=1$, the power spectrum of precursor waves is relatively broad (fractional width $\sim 1-3$) for cold temperatures, whereas it shows pronounced line-like features with fractional width $\sim 0.2$ for $10^{-3} \lesssim Δγ\lesssim 10^{-1.5} $. For $σ\gtrsim 1$, the precursor waves are beamed within an angle $\simeq σ^{-1/2}$ from the shock normal (as measured in the post-shock frame), as required so they can outrun the shock. Our results can provide physically-grounded inputs for FRB emission models based on maser emission from relativistic shocks.
