Periodic Repeating Fast Radio Bursts: Interaction between a Magnetized Neutron Star and Its Planet in an Eccentric Orbit

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 Alfvén 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.

Arecibo observations of a burst storm from FRB 20121102A in 2016

“…Beniamini, Wadiasingh & Metzger 2020 , although such slow-rotating magnetars have not yet been observed) or the orbital period of a NS in a binary system with another astrophysical object (e.g. Gu, Yi & Liu 2020 ;Lyutikov, Barkov & Giannios 2020 ;Du et al 2021 ;Sridhar et al 2021 ;Wada, Ioka & Zhang 2021 ;Kuerban et al 2022 ). The literature is also divided on the location of the emission region, assuming a NS origin: i.e.…”

Repeating fast radio bursts produced by a strange star interacting with its planet in an eccentric orbit

“…Recently, Kurban et al [28] studied the interaction of a highly magnetized NS with and its planet in a highly eccentric orbit. They suggested that the planet will be partially disrupted when it passes through the periastron.…”

“…In addition to that, various other models have also been proposed and could not be expelled yet [25]. For example, motivated by the atmosphere pollution of white dwarfs (WDs) by heavy elements [26] and the WDplanet/asteroid tidal disruption interactions [27,28] proposed that periodically repeating FRBs may be triggered by a magnetized NS interacting with its planet in a highly eccentric orbit. The planet will be partially tidal disrupted every time it comes to the periastron.…”

“…In this study, the essential ingredients of Kurban et al's [28] and Geng et al's [30] models are incorporated to build a new model for periodically repeating FRBs. We assume that a planet moves around a magnetized SS in a highly eccentric orbit.…”

The Physical Origin of the Periodic Activity for FRB 20180916B

“…These theoretical models make different predictions not only on the temporal evolution of the observed period (Katz 2021;Wei et al 2022), but also on the distribution of various observational parameters, such as DM, polarization angle, and RM. There are also some other models, such as a magnetized pulsar traveling through an asteroid belt in a binary system (Dai & Zhong 2020), a binary system with a neutron star and a white dwarf undergoing mass transfer (Gu et al 2020), a planet partially disrupted by a neutron star at periastron (Kurban et al 2022), and a massive binary consisting of a magnetar and an early-type star (Barkov & Popov 2022). Since they lack of explicit predictions, we will not discuss them in this work.…”