Fast Radio Bursts’ Recipes for the Distributions of Dispersion Measures, Flux Densities, and Fluences
Fast Radio Bursts’ Recipes for the Distributions of Dispersion Measures, Flux Densities, and Fluences
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DOI：
10.3847/1538-4357/aab9a9
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发表时间：
2018-01
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影响因子：
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通讯作者：
Y. Niino
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文献类型：
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作者：
Y. Niino
我们研究了如何通过未知的宇宙速率密度历史 [ρFRB(z)] 和瞬态事件的光度函数 (LF) 来确定色散测量 (DM) 和（非重复）快速射电爆发 (FRB) 的表观通量密度/注量的统计特性。我们使用 ρFRB(z) 和 LF 的分析模型，考虑波束内接收器效率的变化，预测 DM、通量密度和 FRB 注量的分布。将预测与观测结果进行比较，我们发现表观注量的累积分布表明 FRB 起源于宇宙学距离，并且 ρFRB 随着红移而增加，类似于宇宙恒星形成历史 (CSFH)。我们还表明，如果 ρFRB(z) ∝ CSFH，则亮端截止值为 log10Lν (erg s−1 Hz−1) ∼ 34 的 LF 模型有利于重现观察到的 DM 分布，尽管使用当前观察样本大小获得的约束的统计显着性不高。最后，我们发现 DM 和 FRB 通量密度之间的相关性可能是一个强大的工具，可以通过未来的观测更可靠地区分 FRB 是在宇宙学距离处还是在局部宇宙中。
We investigate how the statistical properties of dispersion measure (DM) and apparent flux density/fluence of (nonrepeating) fast radio bursts (FRBs) are determined by unknown cosmic rate density history [ρFRB(z)] and luminosity function (LF) of the transient events. We predict the distributions of DMs, flux densities, and fluences of FRBs taking account of the variation of the receiver efficiency within its beam, using analytical models of ρFRB(z) and LF. Comparing the predictions with the observations, we show that the cumulative distribution of apparent fluences suggests that FRBs originate at cosmological distances and ρFRB increases with redshift resembling the cosmic star formation history (CSFH). We also show that an LF model with a bright-end cutoff at log10Lν (erg s−1 Hz−1) ∼ 34 are favored to reproduce the observed DM distribution if ρFRB(z) ∝ CSFH, although the statistical significance of the constraints obtained with the current size of the observed sample is not high. Finally, we find that the correlation between DM and flux density of FRBs is potentially a powerful tool to distinguish whether FRBs are at cosmological distances or in the local universe more robustly with future observations.