论文标题

在条纹喷气机模型中将余辉与提示GRB和中央发动机连接起来

Connecting the early afterglow to the prompt GRB and the central engine in the striped jet model

论文作者

Damoulakis, Michail, Duran, Rodolfo Barniol, Giannios, Dimitrios

论文摘要

尽管描述伽马射线爆发(GRB)余气的框架普遍接受,但中央发动机对紧凑型物体的性质和及时发射后的机制仍在争论中。条纹射流模型是连接各种GRB阶段的有前途的场所,因为它为射流散装加速度,磁化和耗散曲线的关系提供了强大的预测,这是距离的函数。在这里,我们使用射流流的磁化和块状洛伦兹的约束,在大尺度上,射流开始与大量突发样本中的射流开始与环境气体相互作用,以(i)测试GRB流量的条纹射流模型,(ii)研究其及时发射的预测以及中央发动机本质的约束。我们发现,该模型预测的发射光度成分的峰与我们样品中大多数突发的观察到的迅速发射光谱一致,辐射效率约为10%。此外,我们采用两种不同的方法将爆发的峰值能量与中央发动机的类型相关联,发现与黑洞相比,更多的爆发与中子星中心发动机兼容。最后,我们得出的结论是,该模型有利于条纹长度尺度的更广泛的分布,与射流条具有单个长度尺度的特征相比,这会导致更逐渐的耗散曲线。

Despite a generally accepted framework for describing the Gamma-Ray Burst (GRB) afterglows, the nature of the compact object at the central engine and the mechanism behind the prompt emission remain debated. The striped jet model is a promising venue to connect the various GRB stages since it gives a robust prediction for the relation of jet bulk acceleration, magnetization and dissipation profile as a function of distance. Here, we use the constraints of the magnetization and bulk Lorentz of the jet flow at the large scales where the jet starts interacting with the ambient gas in a large sample of bursts to (i) test the striped jet model for the GRB flow and (ii) study its predictions for the prompt emission and the constraints on the nature of the central engine. We find that the peak of the photospheric component of the emission predicted by the model is in agreement with the observed prompt emission spectra in the majority of the bursts in our sample, with a radiative efficiency of about 10 per cent. Furthermore, we adopt two different approaches to correlate the peak energies of the bursts with the type of central engine to find that more bursts are compatible with a neutron star central engine compared to a black hole one. Lastly, we conclude that the model favors broader distribution of stripe length-scales which results in a more gradual dissipation profile in comparison to the case where the jet stripes are characterized by a single length-scale.

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