论文标题
通过使用Baryon加载来限制GRB 170817A的喷气发射时间
Constraining the Jet Launching Time of GRB 170817A by Utilizing the Baryon Loading
论文作者
论文摘要
GRB 170817A相对于GW170817的观察到的延迟提供了有关伽马射线爆发（GRB）物理学的重要信息，并且可能会进行激烈的争论。在这封信中，我们提出了一种讨论此时间延迟的主要来源的方法。首先，我们使用结构化的喷气模型来拟合GRB 170817A的X射线/光学/无线电余星，以及由非常长的基线干涉测量法测量的超光运动。我们的结构化射流以角度依赖的能量和重子负载进行建模。发现我们的模型可以很好地适合GRB 170817a的余辉。之后，根据我们的拟合结果来推断喷气机中的重载。通过将巴里昂的负载与不同阶段的质量流出进行比较，我们推断出，相对于合并，喷气机的时间滞后少于数百或数十毫秒。这表明GRB 170817A相对于GW170817的时间延迟主要是由于喷气机的扩散时间传播到其耗散半径。
The observed delay of GRB 170817A relative to GW170817 carries significant information about gamma-ray burst (GRB) physics and is subject to intense debate. In this letter, we put forward an approach to discuss the major source of this time delay. First of all, we use the structured jet model to fit the X-ray/optical/radio afterglows of GRB 170817A together with superluminal motion measured by the Very Long Baseline Interferometry. Our structured jet is modelled with angle-dependent energy and baryon loading. It is found that our model can well fit the afterglows of GRB 170817A. After that, the baryon loading in the jet is inferred based on our fitting results. By comparing the baryon loading to the mass outflow in different stages, we infer that the time lag of the jet launch relative to the merger is less than hundreds or tens of milliseconds. It suggests that the time delay of GRB 170817A relative to GW170817 is defined mostly by the spreading time of the jet propagating to its dissipation radius.
