The pulse morphology of fast radio bursts (FRBs) provides key information in both understanding progenitor physics and the plasma medium through which the burst propagates. We present a study of the profiles of 33 bright FRBs detected by the Australian Square Kilometre Array Pathfinder. We identify seven FRBs with measureable intrinsic pulse widths, including two FRBs that have been seen to repeat. In our modest sample we see no evidence for bimodality in the pulse width distribution. We also identify five FRBs with evidence of millisecond timescale pulse broadening caused by scattering in inhomogeneous plasma. We find no evidence for a relationship between pulse broadening and extragalactic dispersion measure. The scattering could be either caused by extreme turbulence in the host galaxy or chance propagation through foreground galaxies. With future high time resolution observations and detailed study of host galaxy properties we may be able to probe line-of-sight turbulence on gigaparsec scales.

中文翻译：

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ASKAP 快速射电暴脉冲展宽的总体分析

快速射电暴 (FRB) 的脉冲形态为理解前身物理学和爆发传播的等离子体介质提供了关键信息。我们对澳大利亚平方公里阵列探路者探测到的 33 个明亮 FRB 的轮廓进行了研究。我们确定了七个具有可测量固有脉冲宽度的 FRB，其中包括两个已被观察到重复的 FRB。在我们适度的样本中，我们没有看到脉冲宽度分布中存在双峰的证据。我们还确定了五个 FRB，这些 FRB 具有由不均匀等离子体中的散射引起的毫秒时间尺度脉冲展宽的证据。我们没有发现脉冲展宽与河外色散测量之间存在关系的证据。散射可能是由宿主星系中的极端湍流引起的，也可能是通过前景星系的偶然传播引起的。