Birth and Evolution of Fast Radio Bursts: Strong Population-Based Evidence for a Neutron-Star Origin

TL;DR

This study uses comprehensive population modeling and the entire set of one-off CHIME/FRB data to provide strong evidence that fast radio bursts originate from neutron stars, with implications for their birth rates and host environments.

Contribution

The paper introduces advanced MCMC capabilities in frbpoppy to analyze the full CHIME/FRB dataset, offering the most confident population-based insights into FRB origins to date.

Findings

Approximately 4,000 one-off FRBs occur per second up to redshift 1.

FRB birth rates correlate with the universe's star formation rate.

Evidence supports neutron stars, particularly magnetar-like sources, as FRB progenitors.

Abstract

While the appeal of their extraordinary radio luminosity to our curiosity is undiminished, the nature of fast radio bursts (FRBs) has remained unclear. The challenge has been due in part to small sample sizes and limited understanding of telescope selection effects. We here present the first inclusion of the entire set of one-off FRBs from CHIME/FRB Catalog 1 in frbpoppy. Where previous work had to curate this data set, and fit for few model parameters, we have developed full multi-dimensional Markov chain Monte Carlo (MCMC) capabilities for frbpoppy -- the comprehensive, open-science FRB population synthesis code -- that allow us to include all one-off CHIME bursts. Through the combination of these two advances we now find the best description of the real, underlying FRB population, with higher confidence than before. We show that $4\pm3\times10^{3}$ one-off FRBs go off every second between Earth and $z$=1; and we provide a mock catalog based on our best model, for straight-forward inclusion in other studies. We investigate CHIME side-lobe detection fractions, and FRB luminosity characteristics, to show that some bright, local FRBs are still being missed. We find strong evidence that FRB birth rates evolve with the star formation rate of the Universe, even with a hint of a short (0.1$-$1 Gyr) delay time. The preferred contribution of the hosts to the FRB dispersion agrees with a progenitor birth location in the host disk. This population-based evidence solidly aligns with magnetar-like burst sources, and we conclude FRBs are emitted by neutron stars.