Low-frequency, wideband study of an active repeater, FRB 20240114A, with the GMRT

TL;DR

This study presents low-frequency, wideband observations of the active repeating fast radio burst FRB 20240114A with the GMRT, revealing evolving emission properties, diverse burst characteristics, and complex statistical distributions of waiting times and energies.

Contribution

It provides the first detailed low-frequency, wideband analysis of an active FRB repeater, highlighting evolving emission features and complex statistical behaviors.

Findings

Detected 167 bursts over 6 months with the GMRT.

Burst properties such as flux, width, and scattering vary widely.

Waiting times follow a bi-modal Weibull and log-normal distribution.

Abstract

We report the detection of 167 bursts from an active repeater, FRB 20240114A, using the uGMRT. The observations were carried over a frequency range of 300 $-$ 750 MHz, and on 4 different dates over a period of 6 months. Our analysis indicates that the FRB's emission properties are evolving, with both the median flux and emission rate of the bursts decreasing over time. The properties of the bursts also vary widely, with a wide range of intrinsic widths (0.246 to 39.364 ms), scattering timescales (0.004 to 28.289 ms), dispersion measures (524.07 to 533.56 pc cm$^{-3}$), and band occupancies (9 to 180 MHz). The distribution for the waiting time, $t_{\mathrm{wait}}$, is bi-modal, and follows a Weibull distribution, with a shape parameter $k = 0.33$; however, when the two distributions are fit separately, they follow a Weibull distribution with $k = 0.63$ for $t_{\mathrm{wait}} < 1$ s, and a log-normal distribution with a width of $\sigma = 1.28$ for $t_{\mathrm{wait}} > 1$ s. The isotropic energy distribution is seen to follow a log-normal distribution as well, with a width of $\sigma = 0.83$.