New Insights into Fast Radio Bursts from CHIME's Far Side-Lobe Events

Recent research has provided new insights into fast radio bursts (FRBs), specifically focusing on the far side-lobe events detected by the Canadian Hydrogen Intensity Mapping Experiment (CHIME). The study, titled "Constraints on the Intergalactic and Local Dispersion Measure of Fast Radio Bursts with the CHIME/FRB far side-lobe events," analyzes 10 FRBs detected between August 2018 and August 2021.

Key findings from the research indicate that the far side-lobe events exhibit an average flux approximately 500 times greater than that of events detected in CHIME's main lobe. This suggests that the far side-lobe sample is statistically about 20 times closer than the main-lobe sample.

The study also presents a comparison of the median dispersion measures (DM) for the two populations. The median DM excess for the far side-lobe events is reported as 183.0 pc cm^-3, while for the 471 non-repeating main-lobe FRBs, it is 433.9 pc cm^-3. After accounting for the Galactic disk component, the local contributions from the Milky Way halo and host galaxy, as well as the intergalactic contribution to the excess DM, were statistically constrained. The findings suggest a median redshift of approximately 0.3 for the main-lobe FRB sample.

These constraints are significant for ongoing population studies of FRBs and contribute to understanding the distribution of missing baryons in the universe. The full paper can be accessed here.