Simultaneous multi-telescope observations of FRB 121102

TL;DR

This study reports multiple simultaneous detections of FRB 121102 using MeerKAT and Nancay telescopes, revealing detailed frequency structures, sub-pulse drifting, and precursor signals, advancing understanding of the burst's complex emission behavior.

Contribution

First simultaneous multi-telescope observations of FRB 121102 across a wide frequency band, providing detailed insights into its frequency structure and sub-pulse drifting.

Findings

Detected 11 bursts during active period with detailed frequency analysis

Observed consistent frequency drift rates with previous studies

Identified faint precursors preceding some bursts

Abstract

We present 11 detections of FRB 121102 in ~3 hours of observations during its 'active' period on the 10th of September 2019. The detections were made using the newly deployed MeerTRAP system and single pulse detection pipeline at the MeerKAT radio telescope in South Africa. Fortuitously, the Nancay radio telescope observations on this day overlapped with the last hour of MeerKAT observations and resulted in 4 simultaneous detections. The observations with MeerKAT's wide band receiver, which extends down to relatively low frequencies (900-1670 MHz usable L-band range), have allowed us to get a detailed look at the complex frequency structure, intensity variations and frequency-dependent sub-pulse drifting. The drift rates we measure for the full-band and sub-banded data are consistent with those published between 600-6500 MHz with a slope of -0.147 +/- 0.014 ms^-1. Two of the detected bursts exhibit fainter 'precursors' separated from the brighter main pulse by ~28 ms and ~34 ms. A follow-up multi-telescope campaign on the 6th and 8th October 2019 to better understand these frequency drifts and structures over a wide and continuous band was undertaken. No detections resulted, indicating that the source was 'inactive' over a broad frequency range during this time.