Detection and localisation of the highly active FRB 20240114A with MeerKAT

International audience ; We report observations of the highly active FRB 20240114A with MeerKAT using the Ultra-High Frequency (UHF; 544-1088 MHz) and L-band (856-1712 MHz) receivers. A total of 62 bursts were detected in coherent tied-array beams using the MeerTRAP real-time transient detection pipeline. We measure a structure-optimising dispersion measure of 527.65 ± 0.01 pc cm -3 using the brightest burst in the sample. We find the bursts of FRB 20240114A are generally detected in part of the broad band of MeerKAT, $\sim 40~{{\%}}$ in the UHF and $\sim 30~{{\%}}$ in the L-band, indicating the band limited nature. We analyse the fluence distribution of the 44 bursts detected at UHF, constraining the fluence completeness limit to ~1 Jy ms, above which the cumulative burst rate follows a power law R( > F)∝(F/1 Jy ms) γ with γ = -1.8 ± 0.2. Using channelised telescope data captured in our transient buffer we localise FRB 20240114A in the image domain to RA = 21h27m39.86s, Dec = +04d19m45.01s with an uncertainty of 1.4 arcsec. This localisation allows us to confidently identify the host galaxy of FRB 20240114A. Also using the transient buffer data we perform a polarimetric study and demonstrate that most of the bursts have $\sim 100~{{\%}}$ linear polarisation fractions and up to $\sim 20~{{\%}}$ circular polarisation fractions. Finally, we predict the flux density of a potential persistent radio source (PRS) associated with FRB 20240114A is ⋍[0.6-60] μJy based on the simple relation between the luminosity of the PRS and the rotation measure arising from the FRB local environment.