Fast radio bursts' recipes for the distributions of dispersion measures, flux densities, and fluences

TL;DR

This paper models the statistical distributions of dispersion measures, flux densities, and fluences of non-repeating fast radio bursts to infer their cosmic origins, luminosity functions, and potential for future distance determination.

Contribution

It introduces analytical models linking FRB distributions to cosmic rate density and luminosity functions, providing insights into their cosmological distances and origins.

Findings

FRBs likely originate at cosmological distances with a rate increasing with redshift.

A luminosity function with a bright-end cutoff around 10^34 erg s^-1 Hz^-1 fits observed data.

DM-flux density correlation can help distinguish between local and cosmological FRB origins.

Abstract

We investigate how the statistical properties of dispersion measure (DM) and apparent flux density/fluence of (non-repeating) fast radio bursts (FRBs) are determined by unknown cosmic rate density history [$\rhoFRB (z)$] 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 $\rhoFRB (z)$ 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 $\rhoFRB$ increases with redshift resembling cosmic star formation history (CSFH). We also show that a LF model with a bright-end cutoff at log$_{10}L_\nu$ [erg s$^{-1}$Hz$^{-1}$] $\sim$ 34 are favored to reproduce the observed DM distribution if $\rhoFRB (z)\propto$ 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.