Repeating Fast Radio Bursts Reveal Memory from Minutes to an Hour

Fast radio bursts (FRBs) are brief, luminous pulses with unknown physical origin. The repetition pattern of FRBs contains essential information about their physical nature and emission mechanisms. Using the two largest samples of FRB 20121102 and FRB 20201124A, we report that the sources of the two FRBs reveal memory over a large range of timescales, from a few minutes to about an hour. The memory is detected from the coherent growths in burst-rate structures and the Hurst exponent. The waiting time distribution displays an approximate power-law tail, which is consistent with a Poisson model with a time-varying rate. From cellular automaton simulations, we find that these characteristics can be well understood within the physical framework of a self-organized criticality system driven in a correlation way, such as random walk functions. These properties indicate that the triggers of bursts are correlated, preferring the crustal failure mechanism of neutron stars.

Automated summary

Research has found that the repetition pattern of FRBs shows a large range of time memory, from a few minutes to about an hour. This memory is detected through burst-rate structures and the Hurst exponent. The waiting time distribution follows an approximate power-law tail, consistent with a time-varying Poisson model. Simulations suggest that these characteristics can be explained within a self-organized criticality system driven in a correlation way, such as random walk functions. These properties indicate a correlated triggering mechanism, favoring the crustal failure mechanism of neutron stars.