论文标题

快速无线电爆发的能量和红移分布

On the energy and redshift distributions of fast radio bursts

论文作者

Zhang, Rachel C., Zhang, Bing, Li, Ye, Lorimer, Duncan R.

论文摘要

快速无线电爆发(FRB)是从宇宙学距离进行的毫秒无线电瞬变。他们的各向同性能量遵循具有指数截止的幂律分布,但是他们的内在红移分布(包含有关FRB来源的信息)尚不清楚。我们试图通过蒙特卡洛模拟来限制这两个分布,并将模拟结果与可用的FRB特异性平均分布,分散度量(DM)分布和估计的能量分布数据进行比较。测试了两个红移分布模型,一种跟踪宇宙的星形形成历史记录和另一个跟踪紧凑的二进制合并。对于后一种模型,我们考虑三个合并延迟时间尺度分布(高斯,逻辑正常和权力定律)模型。 Parkes和澳大利亚平方公里阵列探路者(ASKAP)检测到的两个FRB样品分别用于面对模拟结果。我们确认$ \ sim -1.8 $ Power Law指数用于能量分布,但分配的指数截止能量(如果有)不受限制。对于最佳的能量分布模型,我们认为的红移分布都没有被数据拒绝。未来,较大,均匀的FRB样品(例如加拿大氢强度映射实验收集的一个样本,Chime)可以使用本文介绍的方法对固有的FRB红移分布提供更好的约束。

Fast radio bursts (FRBs) are millisecond-duration radio transients from cosmological distances. Their isotropic energies follow a power-law distribution with a possible exponential cutoff, but their intrinsic redshift distribution, which contains information about the FRB sources, is not well understood. We attempt to constrain both distributions by means of Monte Carlo simulations and comparing the simulations results with the available FRB specific fluence distribution, dispersion measure (DM) distribution, and the estimated energy distribution data. Two redshift distribution models, one tracking the star formation history of the universe and another tracking compact binary mergers, are tested. For the latter model, we consider three merger delay timescale distribution (Gaussian, log-normal, and power law) models. Two FRB samples detected by Parkes and the Australian Square Kilometre Array Pathfinder (ASKAP), respectively, are used to confront the simulation results. We confirm the $\sim -1.8$ power law index for the energy distribution but the exponential cutoff energy of the distribution, if any, is unconstrained. For the best energy distribution model, none of the redshift distributions we considered are rejected by the data. A future, larger, uniform FRB sample (such as the one collected by the Canadian Hydrogen Intensity Mapping Experiment, CHIME) can provide better constraints on the intrinsic FRB redshift distribution using the methodology presented in this paper.

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