Can a Single Population Account for the Discriminant Properties in Fast Radio Bursts?

TL;DR

This study analyzes CHIME/FRB data to determine if a single population explains the differences between repeating and non-repeating fast radio bursts, finding evidence for potentially two distinct populations based on spectral properties.

Contribution

The paper provides a statistical analysis of FRB properties, revealing that some differences cannot be explained by beamed emission, suggesting the existence of two separate populations.

Findings

Repetition rate and duration differences may be due to selection effects.

Spectral index and peak frequency differences suggest two populations.

Some properties are consistent with a single population under beamed emission models.

Abstract

To probe this question, we perform a statistical analysis using the first Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) catalog and identify a few discriminant properties between repeating and non-repeating FRBs such as the repetition rate, duration, bandwidth, spectral index, peak luminosity, and potential peak frequency. If repeating and non-repeating FRBs belong to one population, their distribution distinctions for the repetition rate and duration can be explained by the selection effect due to the beamed emission as in Connor et al. (2020). However, we obtain that the distribution distinctions for the spectral index and potentially the peak frequency cannot be explained by the beamed emission within the framework of either the coherent curvature radiation or synchrotron maser emission. This indicates that there could be two populations. We further discuss three possible scenarios for the required two populations.