Periodic repeating fast radio bursts: interaction between a magnetized neutron star and its planet in an eccentric orbit

TL;DR

This paper proposes a new model where periodic repeating fast radio bursts are caused by interactions between a magnetized neutron star and a close-orbiting planet in an eccentric orbit, explaining observed periodicities.

Contribution

The study introduces a novel neutron star-planet interaction model to explain periodic repeating FRBs, emphasizing the role of tidal disruption and the Alfvén wing mechanism.

Findings

Model explains FRB periodicity from days to hundreds of days.

Consistent with observed behaviors of FRBs 121102 and 180916.

Eccentric orbit and tidal disruption are key factors.

Abstract

Fast radio bursts (FRBs) are mysterious transient phenomena. The study of repeating FRBs may provide useful information about their nature due to their redetectability. The two most famous repeating sources are FRBs 121102 and 180916, with a period of 157 days and 16.35 days, respectively. Previous studies suggest that the periodicity of FRBs is likely associated with neutron star (NS) binary systems. Here we introduce a new model which proposes that periodic repeating FRBs are due to the interaction of a NS with its planet in a highly elliptical orbit. The periastron of the planet is very close to the NS so that it would be partially disrupted by tidal force every time it passes through the periastron. Fragments generated in the process could interact with the compact star through the Alfv\'{e}n wing mechanism and produce FRBs. The model can naturally explain the repeatability of FRBs with a period ranging from a few days to several hundred days, but it generally requires that the eccentricity of the planet's orbit should be large enough. Taking FRBs 121102 and 180916 as examples, it is shown that the main features of the observed repeating behaviors can be satisfactorily accounted for.