Compelling Morphologies of Fast Radio Bursts with CHIME/FRB Baseband Data

Jakob Faber ( Université McGill )


Fast Radio Bursts (FRBs) are a class of highly luminous extragalactic radio transients that occur on micro-to-millisecond timescales. While the majority of FRB sources appear to emit only once, an increasing number of sources have been discovered to emit repeatedly. Investigations into the underlying progenitors and emission mechanisms of FRBs, the likes of which remain a mystery, have largely been limited by the availability of data at sufficiently high time and frequency resolutions with full-polarization information. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) has detected thousands of repeating and non-repeating FRBs, hundreds of which we now have the capability to study morphologically and polarimetrically at a high time resolution of 2.56 us using baseband (raw voltage) data. From this rich sample of high-resolution data, we have selected sixteen one-off FRBs and two bursts from repeating sources that exhibit morphologies of compelling complexity. These events were chosen based on their brightness and suggestive consistency (or lack thereof) with models of FRBs that have been put forward in the field thus far. Motivated by this diverse gallery of events, I show how we can draw new insights into emission mechanism and progenitor models of FRBs, paying particular attention to relativistic shock and magnetospheric scenarios. I also discuss the extent to which their morphologies and polarization properties can be explained by propagation through intervening media.