The association of FRB 200428 with the Galactic magnetar SGR 1935+2154 confirms that magnetars can power fast radio bursts (FRBs). However, FRB 200428 is 4 to 8 orders of magnitude less energetic than the typical population of cosmological FRBs. This discrepancy is likely due to the moderate magnetic field strength and evolved age of SGR 1935+2154. In contrast, newborn extragalactic magnetars, such as those formed in gamma-ray burst (GRB) central engines, are expected to have much stronger magnetic fields, more rapid spin-down, and highly dynamic magnetospheres, all of which favor the production of brighter and more frequent FRBs.
We propose a targeted search for FRBs from the recently localized GRB 230307A, a long-duration GRB with evidence suggesting the formation of a young magnetar. Given the source's relatively close distance (291 Mpc) and possible youth (less than 3 years), it offers a compelling opportunity to test FRB generation mechanisms during the early evolution of a magnetar.
We request 30 hours of observing time with the Parkes 64-m Murriyang telescope using the ultra-wideband low-frequency (UWL) receiver. Our plan includes one 10-hour long-duration session to detect rare or clustered bursts, and ten 2-hour sessions spread over 2-3 months to sample temporal variability. Data will be processed with state-of-the-art pipelines for single-pulse searches and coherent dedispersion.
A detection would strongly support magnetar-origin FRB models and provide key constraints on the early-time activity of GRB-formed neutron stars.
