Precise measurements of self-absorbed rising reverse shock emission from gamma-ray burst 221009A
Precise measurements of self-absorbed rising reverse shock emission from gamma-ray burst 221009A
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DOI：
10.1038/s41550-023-01997-9
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发表时间：
2023-03
期刊：
影响因子：
14.1
通讯作者：
J. Bright;L. Rhodes;W. Farah;R. Fender;A. J. van der Horst;J. Leung;David R. A. Williams;G. Anderson;P. Atri;D. DeBoer;S. Giarratana;D. Green;I. Heywood;E. Lenc;T. Murphy;A. Pollak;P. Premnath;P. Scott;Sofia Z. Sheikh;A. Siemion;D. Titterington
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文献类型：
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作者：
J. Bright;L. Rhodes;W. Farah;R. Fender;A. J. van der Horst;J. Leung;David R. A. Williams;G. Anderson;P. Atri;D. DeBoer;S. Giarratana;D. Green;I. Heywood;E. Lenc;T. Murphy;A. Pollak;P. Premnath;P. Scott;Sofia Z. Sheikh;A. Siemion;D. Titterington
大质量恒星的死亡有时伴随着高度相对论性和准直喷流的发射。如果喷流指向地球，我们会观察到由于喷流内部的内部冲击或磁重联事件而导致的“即时”伽马射线爆发，然后是喷流与环暴物质相互作用时的长寿命宽带同步加速器余辉。虽然有可靠的观测证据表明，来自多次冲击的辐射有助于余辉特征，但由于缺乏早期观测，特别是在无线电波段，对反向冲击的详细研究受到阻碍，反向冲击会返回爆炸喷出物。我们提出了快速的后续无线电观测异常明亮的伽玛射线暴GRB 221009A，详细揭示，无论是在时间上和频率空间，光学厚上升组件从反向冲击。由此，我们能够约束的大小，洛伦兹因子和内部能量的流出，同时提供准确的预测的位置的峰值频率的反向冲击波后的头几个小时。这些观测结果挑战了描述反向冲击辐射的标准伽马射线暴模型。
The deaths of massive stars are sometimes accompanied by the launch of highly relativistic and collimated jets. If the jet is pointed towards Earth, we observe a ‘prompt’ gamma-ray burst due to internal shocks or magnetic reconnection events within the jet, followed by a long-lived broadband synchrotron afterglow as the jet interacts with the circumburst material. While there is solid observational evidence that emission from multiple shocks contributes to the afterglow signature, detailed studies of the reverse shock, which travels back into the explosion ejecta, are hampered by a lack of early-time observations, particularly in the radio band. We present rapid follow-up radio observations of the exceptionally bright gamma-ray burst GRB 221009A that reveal in detail, both temporally and in frequency space, an optically thick rising component from the reverse shock. From this, we are able to constrain the size, Lorentz factor and internal energy of the outflow while providing accurate predictions for the location of the peak frequency of the reverse shock in the first few hours after the burst. These observations challenge standard gamma-ray burst models describing reverse shock emission.