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A bright radio burst was newly discovered in SGR 1935+2154, which exhibit some FRB-like temporal- and frequency-properties, suggesting a neutron star (NS)/magnetar magnetospheric origin of FRBs. We propose an explanation of the temporal- and frequency-properties of sub-pulses of repeating FRBs based on the generic geometry within the framework of charged-bunching coherent curvature radiation in the magnetosphere of an NS. The sub-pulses in a radio burst come from bunches of charged particles moving along different magnetic field lines. Their radiation beam sweep across the line of sight at slightly different time, and those radiating at the more curved part tend to be seen earlier and at higher frequency. However, by considering bunches generated at slightly different times, we find there is also a small probability that the emission from the less curved part be seen earlier. We simulate the time--frequency structures by deriving various forms of the electric acceleration field in the magnetosphere. Such structure of sub-pulses is a natural consequence of coherent curvature radiation from an NS magnetosphere with suddenly and violently triggered sparks. We apply this model to explain the time--frequency structure within specific dipolar configuration by invoking the transient pulsar-like sparking from the inner gap of a slowly rotating NS, and have also developed in more generic configurations.
Fast spinning (e.g., sub-second) neutron star with ultra-strong magnetic fields (or so-called magnetar) is one of the promising origins of repeating fast radio bursts (FRBs). Here we discuss circularly polarised emissions produced by propagation effe
Repeating fast radio bursts (FRBs) present excellent opportunities to identify FRB progenitors and host environments, as well as decipher the underlying emission mechanism. Detailed studies of repeating FRBs might also hold clues to the origin of FRB
Fast radio burst (FRBs) are an exciting class of bright, extragalactic, millisecond radio transients. The recent development of large field-of-view (FOV) radio telescopes has caused a rapid rise in the number of identified single burst and repeating
High-precision cosmological probes have revealed a small but significant tension between the parameters measured with different techniques, among which there is one based on time delays in gravitational lenses. We discuss a new way of using time dela
The origin of fast radio bursts (FRBs) is still a mystery. One model proposed to interpret the only known repeating object, FRB 121102, is that the radio emission is generated from asteroids colliding with a highly magnetized neutron star (NS). With