论文标题
伽玛射线爆发余星的多波带同步偏振
Multi-Wave band Synchrotron Polarization of Gamma-Ray Burst Afterglows
论文作者
论文摘要
在前进震动的下游中，在各向异性湍流磁场的假设下，研究了伽马射线爆发（GRB）辐射的多波带同步偏振（GRB）辐射的线性极化。我们发现，对于典型的GRB，与光学极化相比，无线电极化程度显示出相似的时间演化，但峰值明显较小。这是由于无线电带和光条之间观察到的强度图像形状的差异所致。我们还表明，极化光谱的程度经历了高于光谱峰频率强度高的高极化状态的逐渐变化，并且两个状态中极化角度的差异为零或90度。因此，GRB余辉的同时多波带极化观察结果将是对等离子体尺度磁场模型的新决定性测试。我们还通过使用ALMA和其他磁场构型模型在GRB 171205a中对射线线性极化的最新检测进行了理论含义。
Multi-wave band synchrotron linear polarization of gamma-ray burst (GRB) afterglows is studied under the assumption of an anisotropic turbulent magnetic field with a coherence length of the plasma skin-depth scale in the downstream of forward shocks. We find that for typical GRBs, in comparison to the optical polarization, the degree of radio polarization shows a similar temporal evolution but a significantly smaller peak value. This results from differences in observed intensity image shapes between the radio and optical bands. We also show that the degree of the polarization spectrum undergoes a gradual variation from the low- to the high-polarization regime above the intensity of the spectral peak frequency, and that the difference in polarization angles in the two regimes is zero or 90 degrees. Thus, simultaneous multi-wave band polarimetric observations of GRB afterglows would be a new determinative test of the plasma-scale magnetic field model. We also discuss theoretical implications from the recent detection of radio linear polarization in GRB 171205A with ALMA and other models of magnetic field configuration.
