Fast radio burst repeaters produced via Kozai-Lidov feeding of neutron stars in binary systems

Abstract

Neutron stars are likely surrounded by gas, debris, and asteroid belts. Kozai-Lidov perturbations, induced by a distant, but gravitationally bound companion, can trigger the infall of such orbiting bodies onto a central compact object. These effects could lead to the emission of fast radio bursts (FRBs), for example by asteroid-induced magnetic wake fields in the wind of the compact object. A few percent of binary neutron star systems in the Universe, such as neutron star-main sequence star, neutron star-white dwarf, double neutron star, and neutron star-black hole systems, can account for the observed non-repeating FRB rates. More remarkably, we find that wide and close companion orbits lead to non-repeating and repeating sources, respectively, and they allow for one to compute a ratio between repeating and non-repeating sources of a few percent, which is in close agreement with the observations. Three major predictions can be made from our scenario, which can be tested in the coming years: (1) most repeaters should stop repeating after a period between 10 years to a few decades, as their asteroid belts become depleted; (2) some non-repeaters could occasionally repeat, if we hit the short period tail of the FRB period distribution; and (3) series of sub-Jansky level short radio bursts could be observed as electromagnetic counterparts of the mergers of binary neutron star systems.