Modeling the GRB 170202A Fireball from Continuous Observations with the Zadko and the Virgin Island Robotic Telescopes
Modeling the GRB 170202A Fireball from Continuous Observations with the Zadko and the Virgin Island Robotic Telescopes
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DOI：
10.3847/1538-4357/ac561e
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发表时间：
2022-02
期刊：
影响因子：
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通讯作者：
B. Gendre;N. Orange;E. Moore;A. Klotz;D. Coward;T. Giblin;P. Gokuldass;D. Morris
中科院分区：
文献类型：
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作者：
B. Gendre;N. Orange;E. Moore;A. Klotz;D. Coward;T. Giblin;P. Gokuldass;D. Morris
我们介绍了Zadko和维尔京岛机器人望远镜对GRB 170202A的协调观测。观测在事件发生59秒后开始，由于这些望远镜的独特位置，观测几乎持续了两天。我们清楚地探测到光学发射的早期上升，随后是后期的光学耀斑。通过与档案观测数据的补充，我们表明，如果考虑到多次反向冲击，GRB 170202A可以很好地用标准火球模型来描述。它的火球被证明是在恒定密度的星际介质中膨胀的，大多数爆发参数与文献中发现的通常范围一致。电子和磁能参数（ε, ε B）比通常假设的值小几个数量级。我们认为，在获得足够全面的数据集之前，我们的研究实现的火球模型的全局拟合应该是可能的。这一结论强调了伽马射线爆发协调观测活动的重要性，比如这项工作的核心，以回答有关驱动这些现象的潜在物理的悬而未决的问题。
We present coordinated observations of GRB 170202A carried out by the Zadko and the Virgin Island Robotic Telescopes. The observations started 59 s after the event trigger, and provided nearly continuous coverage for two days, due to the unique locations of these telescopes. We clearly detected an early rise in optical emission, followed by late optical flares. By complementing these data with archival observations, we show that GRB 170202A is well described by the standard fireball model if multiple reverse shocks are taken into account. Its fireball is evidenced as expanding within a constant-density interstellar medium, with most burst parameters being consistent with the usual ranges found in the literature. The electron and magnetic energy parameters (ϵ e , ϵ B ) are orders of magnitude smaller than the commonly assumed values. We argue that the global fit of the fireball model achieved by our study should be possible for any burst, pending the availability of a sufficiently comprehensive data set. This conclusion emphasizes the crucial importance of coordinated observation campaigns of gamma-ray bursts, such as the one central to this work, to answer outstanding questions about the underlying physics driving these phenomena.