明亮伽马射线暴瞬时辐射中自组织临界性的证据
Evidence of self-organized criticality in the prompt emission of a bright gamma-ray burst
浏览论文内容
中文总结 AI 辅助
本文通过分析GRB 230307A的瞬时辐射脉冲，发现其符合自组织临界性理论，首次为单个GRB瞬时辐射中的SOC特征提供可靠证据，支持磁能主导的GRB瞬时辐射模型。
中文摘要 AI 辅助
伽马射线暴（GRB）是宇宙中能量最高的爆炸事件，但其瞬时辐射的物理机制仍是未解之谜，尤其GRB喷流中的能量耗散机制是由动能主导还是磁能主导尚不明确。本文研究了迄今第二亮的GRB——GRB 230307A的瞬时辐射脉冲，该天体由引力波高能电磁对应体全天空监测器（GECAM）精准测量，研究重点为脉冲峰值计数、持续时间的累积分布以及脉冲间的等待时间。研究发现，这些累积分布呈现出尺度不变行为，与自组织临界性（SOC）理论的预测高度吻合，这是单个GRB瞬时辐射中SOC特征的首个可靠证据。此外，GRB 230307A瞬时辐射脉冲的统计特性与太阳耀斑非常相似。研究结果表明，GRB的瞬时辐射由超相对论喷流中的磁能耗散驱动，支持以坡印廷通量主导的瞬时辐射模型。
英文摘要
Gamma-ray bursts (GRBs) are the most energetic explosive events in the Universe, yet the physical mechanism of their prompt emission remains a mystery. Especially, it is unclear whether the energy dissipation mechanism in the GRB jet is dominated by kinetic energy or magnetic energy. Here, we studied the pulses in the prompt emission of the second brightest GRB to date, GRB 230307A, which was accurately measured by the Gravitational wave high-energy electromagnetic counterpart all-sky monitor (GECAM), with focus on the cumulative distributions of peak counts and duration of pulses as well as the waiting time between pulses. We find that these cumulative distributions show scale-invariant behavior, well consistent with the prediction of the self-organized criticality (SOC) theory. This is the first robust evidence of an SOC feature in the prompt emission of a single GRB. Moreover, the statistical properties of pulses in the prompt emission of GRB 230307A are very similar to those of solar flares. Our findings suggest that the prompt emission of GRB is powered by the dissipation of magnetic energy in the ultra-relativistic jet, supporting the Poynting-flux-dominated prompt models.
