A sample of fast radio bursts discovered and localized with MeerTRAP at the MeerKAT telescope

We present a sample of well-localized fast radio bursts (FRBs) discovered by the MeerTRAP project at the MeerKAT telescope in South Africa. We discovered the three FRBs in single coherent tied-array beams and localized them to an area of similar to 1 arcmin(2). We investigate their burst properties, scattering, repetition rates, and localizations in a multiwavelength context. FRB 20201211A shows hints of scatter broadening but is otherwise consistent with instrumental dispersion smearing. For FRB 20210202D, we discovered a faint post-cursor burst separated by similar to 200 ms, suggesting a distinct burst component or a repeat pulse. We attempt to associate the FRBs with host galaxy candidates. For FRB 20210408H, we tentatively (0.35-0.53 probability) identify a compatible host at a redshift similar to 0.5. Additionally, we analyse the MeerTRAP survey properties, such as the survey coverage, fluence completeness, and their implications for the FRB population. Based on the entire sample of 11 MeerTRAP FRBs discovered by the end of 2021, we estimate the FRB all-sky rates and their scaling with the fluence threshold. The inferred FRB all-sky rates at 1.28 GHz are 8.2(-4.6)(+8.0) and 2.1(-1.1)(+1.8) x 10(3) sky(-1) d(-1) above 0.66 and 3.44 Jy ms for the coherent and incoherent surveys, respectively. The scaling between the MeerTRAP rates is flatter than at higher fluences at the 1.4 sigma level. There seems to be a deficit of low-fluence FRBs, suggesting a break or turn-over in the rate versus fluence relation below 2 Jy ms. We speculate on cosmological or progenitor-intrinsic origins. The cumulative source counts within our surveys appear consistent with the Euclidean scaling.

Automated summary

We discovered well-localized fast radio bursts (FRBs) using the MeerKAT telescope in South Africa. Through our investigation, we found indications of scatter broadening in one FRB while another FRB displayed a faint post-cursor burst, suggesting a distinct burst component or a repeat pulse. We also attempted to identify host galaxy candidates for the FRBs.