Low-frequency study of the hyperactive repeater, FRB 20240114A with the GMRT

Abstract

While most FRBs have been one-off events, a minor fraction (7%) repeats; these are known as repeaters. An even smaller fraction is known as hyperactive repeaters, due to the large number of bursts emitted by them over a short amount of time. Currently, only 5 hyperactive repeaters are known: 20121102A, 20190520B, 20201124A, 20220912A, and 20240114A. In this presentation, we will present the study of 167 bursts detected from FRB 20240114A using the GMRT, over a frequency range of 300 to 750 MHz, and on 4 different dates over a period of 6 months, amounting to more than 18 hours of on-source time. In this presentation, we will talk about our analysis, done using scarab (https://github.com/astrogewgaw/scarab), a new package we developed for the same. The detected bursts showed rich spectro-temporal structure, such as band limitation, drifting sub-bursts, and multiple emission components. The properties of the burst showed a wide variation, with widths varying from ~0.2 to ~40 ms, scattering timescales varying from ~0 to ~30 ms, and DMs varying from ~524 pc cm-3 to ~533 pc cm-3. We see non-Poissonian waiting time distributions for the detected bursts, which indicate that the emission process is not inherently random, and may have some long term memory, as has been previously indicated for other FRBs (e.g.: Wang et al. 2024). We also compare the properties and statistics of the detected bursts from FRB 20240114A to other hyperactive repeaters, which allows us to posit that similar emission mechanisms might be responsible for these events.