| Abstract : | Fast Radio Bursts (FRBs) are bright milliseconds duration radio transients, mostly extragalactic in origin. Till today, among a pool of proposed emission mechanisms, the exact emission mechanism is unknown. The polarization properties of bursts and their variation can provide stringent constraints on the emission mechanisms and the local and intervening medium and magnetic fields. For most of the early detections of the FRBs, we don’t have polarization properties measured. The small measured sub-sample shows significant linear polarization and some shows mixture of linear and circular polarization. Experiments such as the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst project are now saving raw voltage data for a large sample of FRBs allowing population-wide studies of polarization properties. A nearly automated polarization pipeline for CHIME/FRB measures the polarization properties by fitting a polarization and instrumental calibration model to time-averaged Stokes Q,U,V spectra. But FRBs with complex structures, especially from repeating FRB sources, can be problematic to handle as the time-averaged spectra will not retain the sub-burst information. For some FRBs, like reported in Xu et al. 2022 and Cho et al. 2020, we see a variations in polarization properties between sub-bursts. We are expanding the existing pipeline to do a spectro-temporal fit for Q, U, and V spectra with multiple sub-components. We will present the framework for the polarization pipeline and preliminary results from the polarization fitting of FRBs |
