A Neutron Star-White Dwarf Binary Model for Repeating Fast Radio Burst 121102

Understand

We propose a compact binary model for the fast radio burst (FRB) repeaters, where the system consists of a magnetic white dwarf (WD) and a neutron star (NS) with strong bipolar magnetic fields.

• When the WD fills its Roche lobe, mass transfer will occur from the WD to the NS through the inner Lagrange point.
• The accreted magnetized materials may trigger magnetic reconnection when they approach the NS surface, and therefore the electrons can be accelerated to an ultra-relativistic speed.
• In this scenario, the curvature radiation of the electrons moving along the NS magnetic field lines can account for the characteristic frequency and the timescale of an FRB.