We compare the dispersion measure (DM) statistics of FRBs detected by the ASKAP and Parkes radio telescopes. We jointly model their DM distributions, exploiting the fact that the telescopes have different survey fluence limits but likely sample the same underlying population. After accounting for the effects of instrumental temporal and spectral resolution of each sample, we find that a fit between the modelled and observed DM distribution, using identical population parameters, provides a good fit to both distributions. Assuming a oneto-one mapping between DM and redshift for an homogeneous intergalactic medium (IGM), we determine the best-fit parameters of the population spectral index, ?̂?, and the power-law index of the burst energy distribution, ?̂?, for different redshift evolutionary models. Whilst the overall best-fit model yields ?̂? = 2.2+0.7 −1.0 and ?̂? = 2.0 +0.3 −0.1, for a strong redshift evolutionary model, when we admit the further constraint of α = 1.5 we favour the best fit ?̂? = 1.5 ± 0.2 and the case of no redshift evolution. Moreover, we find no evidence that the FRB population evolves faster than linearly with respect to the star formation rate over the DM (redshift) range for the sampled population.

中文翻译：

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快速无线电突发色散测量分布

我们比较了 ASKAP 和 Parkes 射电望远镜检测到的 FRB 的色散测量 (DM) 统计数据。我们联合模拟了它们的 DM 分布，利用望远镜具有不同的测量通量限制但可能对相同的潜在人群进行采样的事实。在考虑了每个样本的仪器时间和光谱分辨率的影响后，我们发现建模和观察到的 DM 分布之间的拟合，使用相同的总体参数，为这两种分布提供了良好的拟合。假设均匀星系际介质 (IGM) 的 DM 和红移之间存在一对一映射，我们确定了种群光谱指数 ?̂? 和爆发能量分布的幂律指数 ?̂ 的最佳拟合参数?，对于不同的红移演化模型。虽然整体最佳拟合模型产生 ?̂? = 2。2+0.7 -1.0 和 ?̂? = 2.0 +0.3 -0.1，对于强红移演化模型，当我们承认 α = 1.5 的进一步约束时，我们倾向于最佳拟合 ?̂? = 1.5 ± 0.2 和没有红移演化的情况。此外，我们没有发现任何证据表明 FRB 群体的演化速度比采样群体的 DM（红移）范围内的恒星形成率更快。