Non-Cosmological FRBs from Young Supernova Remnant Pulsars

TL;DR

This paper proposes a non-cosmological model for FRBs involving young pulsars in supernova remnants, explaining high dispersion measures and polarization features, and predicts specific observational signatures.

Contribution

It introduces a novel local supernova remnant pulsar model for FRBs, contrasting with cosmological explanations, and offers testable predictions for future observations.

Findings

High DM explained by young supernova remnant environment

Large Faraday rotation measures indicate local source

Predicted polarization swings and flux distribution patterns

Abstract

We propose a new extragalactic but non-cosmological explanation for fast radio bursts (FRBs) based on very young pulsars in supernova remnants. Within a few hundred years of a core-collapse supernova the ejecta is confined within $\sim$1 pc, providing a high enough column density of free electrons for the observed 375-1600 pc cm$^{-3}$ of dispersion measure (DM). By extrapolating a Crab-like pulsar to its infancy in an environment like that of SN 1987A, we hypothesize such an object could emit supergiant pulses sporadically which would be bright enough to be seen at a few hundred megaparsecs. We hypothesize that such supergiant pulses would preferentially occur early in the pulsar's life when the free electron density is still high, which is why we do not see large numbers of moderate DM FRBs ($\lesssim300$ pc cm$^{-3}$). In this scenario Faraday rotation at the source gives rotation measures (RMs) much larger than the expected cosmological contribution. If the emission were pulsar-like, then the polarization vector could swing over the duration of the burst, which is not expected from non-rotating objects. In this model, the scattering, large DM, and commensurate RM all come from one place which is not the case for the cosmological interpretation. The model also provides testable predictions of the flux distribution and repeat rate of FRBs, and could be further verified by spatial coincidence with optical supernovae of the past several decades and cross-correlation with nearby galaxy maps.