April 23, 2024

Detection of bursts from FRB 20240114A at 2.5 GHz using the Nançay Radio Telescope

We report on the detection of 5 repeat bursts from FRB 20240114A (ATel #16420) using the Nançay Radio Telescope (NRT) at a central frequency of 2.5 GHz. On 18 April 2024 we observed FRB 20240114A for an hour as part of the ECLAT (Extragalactic Coherent Light from Astrophysical Transients) campaign that monitors repeating fast radio bursts (Hewitt et al. 2023). We recorded full Stokes data with 512 MHz of bandwidth (2283-2795 MHz), and frequency and time resolution of 4 MHz and 16 microseconds, respectively (coherently dispersed to a DM of 527.7 pc cm-3). We searched the data using a custom Heimdall-FETCH-based pipeline and detected 5 bursts above a detection S/N threshold of 7 (corresponding to a fluence threshold of about 0.18 Jy ms). The MJD times-of-arrival of the bursts at 2795 MHz (topocentric at NRT) are:

60418.29815054
60418.30476058
60418.31231426
60418.31687870
60418.33012049

The bursts are band-limited, showing spectral structure and emission extending well above 2500 MHz, making these the highest-frequency detections of FRB 20240114A bursts to date. Further analysis of these bursts is ongoing.

ECLAT has been monitoring about a dozen repeating FRBs using the NRT since the beginning of 2022. We target sources for approximately an hour a week, mostly at a center frequency of 1.4 GHz. We are continuing to monitor FRB 20240114A and encourage further observations of FRB 20240114A at higher radio frequencies to ascertain whether the burst activity shows spectral evolution.

Hewitt et al. 2024, The Astronomer's Telegram, No. 16597.