Context : Fast radio bursts are transient radio pulses of extragalactic origin. Their dispersion measure is indicative of the baryon content in the ionized intergalactic medium between the source and the observer. However, inference using unlocalized fast radio bursts is degenerate to the distribution of redshifts of host galaxies. Method: We perform a joint inference of the intergalactic baryon content and the fast radio burst redshift distribution with the use of Bayesian statistics by comparing the likelihood of different models to reproduce the observed statistics in order to infer the most likely models. In addition to two models of the intergalactic medium, we consider contributions from the local environment of the source, assumed to be a magnetar, as well as a representative ensemble of host and intervening galaxies. Results: Assuming that the missing baryons reside in the ionized intergalactic medium, our results suggest that the redshift distribution of observed fast radio bursts peaks at z . 0.6. However, conclusions from different instruments regarding the intergalactic baryon content diverge and thus require additional changes to the observed distribution of host redshifts, beyond those caused by telescope selection effects.

中文翻译：

---

快速射电暴红移分布与星系间重子含量的联合推论

背景：快速射电暴是来自河外的瞬态射电脉冲。它们的色散测量表明源和观察者之间的电离星系际介质中的重子含量。然而，使用非定域快速射电暴的推断退化为宿主星系的红移分布。方法：我们通过比较不同模型的可能性来重现观察到的统计数据，以推断最可能的模型，从而使用贝叶斯统计对星际重子含量和快速射电暴红移分布进行联合推断。除了两个星系际介质模型之外，我们还考虑了来自源的局部环境的贡献，假设是磁星，以及宿主和干预星系的代表性集合。结果：假设丢失的重子存在于电离的星系际介质中，我们的结果表明观察到的快速射电暴的红移分布在 z 处达到峰值。0.6. 然而，不同仪器关于星系间重子含量的结论存在分歧，因此需要对观测到的宿主红移分布进行额外的改变，超出望远镜选择效应引起的改变。