A broad survey of spectro-temporal properties from FRB20121102A

30 Sep 2022  ·  Mohammed A. Chamma, Fereshteh Rajabi, Aishwarya Kumar, Martin Houde ·

We survey the spectro-temporal properties of fast radio bursts from FRB20121102A across a wide range of frequencies. We investigate 167 bursts from FRB20121102A spanning frequencies 1-7.5GHz, durations of less than 1ms to approximately 10ms, with low and high energies, and with wait-times on the order of milliseconds to seconds. We find from our sample of bursts from FRB20121102A a strong agreement with the inverse relationship between sub-burst slope and duration and with other predictions made by the triggered relativistic dynamical model (TRDM). Earlier results found agreement with those predictions across three different repeating FRB sources. For this sample of bursts, we find that the sub-burst slope as well as the `sad trombone' drift rate are consistent with being quadratic with frequency, that both these quantities are inversely proportional to the duration as well as finding that the duration decreases with increasing frequency. We also find a statistically significant correlation between the sub-burst duration and bandwidth (proportional to $t^{-1/2}$) that is unexpected. No distinct group of bursts in this sample deviated from these relationships, however significant dispersion can be seen in measurements. This study demonstrates the consistent existence of relationships between the spectro-temporal properties of bursts from an FRB source, and a simple explanation for the inverse relation between the sub-burst slope and duration is an inherently narrowband emission process. We make available all measurements as well as a graphical user interface called Frbgui developed and used to perform measurements of burst waterfalls.

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