论文标题
SGR 1935+2154的无线电/X射线爆发：辐射机制和可能的QPO
The radio/X-ray burst from SGR 1935+2154: radiation mechanisms and the possible QPOs
论文作者
论文摘要
最近，发现快速无线电爆发（FRB）类似的事件与银河系磁体（SGR 1935+2154）相关，并伴有X射线爆发。我们发现这种无线电爆发挑战了涉及磁铁的典型发射机制，其中包括带电束的连贯曲率辐射，快速磁力（FMS）波，减震器中的同步器MASER以及低扭磁体的Pulsar样机制。更具体地说，我们发现（1）X射线最明显是在磁层内产生的。 （2）对于从Alfvén波的衰减而产生的相干曲率辐射，由于磁场线的强烈曲折和Alfvén波的内部阻尼，它通常会预测持续时间（$ \ \ lysSim0.1 $ ms）。 （3）FMS WAVE模型预测非常低的发射频率$ν_ {\ rm P} \ sim0.03 $ MHz $ \ ll $ GHz，除非它是在磁层内生产的。但是磁层FMS波模型的吸收效果仍有待研究。 （4）挑战同步器MASER模型，因为观察结果表明，X射线和无线电光曲线的峰值均具有相同的时间分离$ΔT_ {\ rm frb} =Δt_γ\ lig0.03 $ s，而它可以预测$ΔT_{\ rm rm frb frb frb $ ll ll ll ll llex_ $ ll llex__ （5）似乎很难将低扭脉冲状的机理直接应用于燃料磁铁中，因为磁性活性可以显着变形磁层。 （6）我们提出了研究FRB的一般特性的四种可能性，尤其是在$ \ sim1-10 $ \ sim1-10 $ ms中以双重/多峰frbs识别出准周期性振荡的可能性。
Recently, a fast radio burst (FRB)-like event is found to be associated with a Galactic magnetar, SGR 1935+2154, accompanied by an X-ray burst. We find this radio burst challenges the typical emission mechanisms involving magnetars, which includes coherent curvature radiation from charged bunches, fast magnetosonic (FMS) wave, synchrotron maser from shocks, and the pulsar-like mechanism for low-twist magnetars. More specifically, we find that (1) the X-rays are most-likely to be produced inside the magnetosphere. (2) For the coherent curvature radiation from the decay of Alfvén wave, it will generally predict a duration ($\lesssim0.1$ ms) smaller than observations, because of the strong twists of magnetic field lines and the internal damping of Alfvén waves. (3) The FMS wave model predicts a very low emission frequency $ν_{\rm p}\sim0.03$ MHz $\ll$ GHz, unless it is produced inside the magnetosphere. But the absorption effect of the magnetospheric FMS wave model remains to be studied. (4) The synchrotron maser model is challenged, because observations show that the peaks in both X-ray and radio light curves are with the same temporal separation $Δt_{\rm FRB}=Δt_γ\approx0.03$ s, while it would predict $Δt_{\rm FRB}\llΔt_γ$. (5) It seems to be difficult to directly apply the low-twist pulsar-like mechanism to flaring magnetars, as magnetar activity can significantly deform the magnetosphere. (6) We suggested four possibilities to study the general properties of FRBs for future observations, especially the possibility of identifying quasi-periodic oscillations with period $\sim1-10$ ms in double/multiple-peaked FRBs.
