Probing the bright radio flare and afterglow of GRB 130427A with the Arcminute Microkelvin Imager
Probing the bright radio flare and afterglow of GRB 130427A with the Arcminute Microkelvin Imager
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DOI：
10.1093/mnras/stu478
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发表时间：
2014-03
影响因子：
4.8
通讯作者：
G. Anderson;A. Horst;T. Staley;R. Fender;R. Wijers;A. Scaife;C. Rumsey;D. Titterington;A. Rowlinson;R. D. E. S. U. Southampton;U. Oxford;U. Amsterdam;U. Cambridge
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作者：
G. Anderson;A. Horst;T. Staley;R. Fender;R. Wijers;A. Scaife;C. Rumsey;D. Titterington;A. Rowlinson;R. D. E. S. U. Southampton;U. Oxford;U. Amsterdam;U. Cambridge
摘要：我们提出了射电波长处伽马射线爆发 (GRB) 的最佳采样早期光曲线之一。使用弧分微开尔文成像仪 (AMI)，我们在爆发后 0.36 至 59.32 天之间观察到中心频率为 15.7 GHz 的 GRB130427A。这些结果产生了伽玛射线暴的最早无线电探测结果之一，并表明在γ射线触发后不到一天的时间内流入量明显上升，随后迅速下降。这种早期射电发射可能起源于 GRB 反向激波，因此我们的 AMI 光曲线揭示了射电域中首次确认的反向激波峰值检测。在稍后的时间（大约爆发后 3:2 天），下降速率降低，表明前向激波分量已开始主导光曲线。 AMI 光曲线与 Perley 等人进行的建模的比较。结果表明，早期 15.7 GHz 峰值最可能的解释是由穿过观测频带的反向激波的自吸收翻转频率而不是峰值频率引起的。 关键词：伽马射线暴：个体：GRB 130427A – 射电连续谱：恒星
ABSTRACT We present one of the best sampled early time light curves of a gamma-ray burst (GRB)at radio wavelengths. Using the Arcminute Mircrokelvin Imager (AMI) we observed GRB130427A at the central frequency of 15.7 GHz between 0.36 and 59.32 days post-burst. Theseresults yield one of the earliest radio detections of a GRB and demonstrate a clear rise influx less than one day after the -ray trigger followed by a rapid decline. This early time radioemission probably originates in the GRB reverse shock so our AMI light curve reveals the firstever confirmed detection of a reverse shock peak in the radio domain. At later times (about 3:2days post-burst) the rate of decline decreases, indicating that the forward shock componenthas begun to dominate the light-curve. Comparisons of the AMI light curve with modellingconducted by Perley et al. show that the most likely explanation of the early time 15.7 GHzpeak is caused by the self-absorption turn-over frequency, rather than the peak frequency, ofthe reverse shock moving through the observing bands.Key words: gamma-ray burst: individual: GRB 130427A – radio continuum: stars