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

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 $\sigma = 0.83$.