A bright double-peaked radio burst from FRB20201124A detected with the Allen Telescope Array
ATel #14676; W. Farah (SETI Institute / University of California, Berkeley "UCB"), A. W. Pollak (SETI / UCB), A. P. V. Siemion (SETI / UCB), F. Antonio (Qualcomm), S. Schoultz (SETI), J. Hickish (Real-time Radio Systems Ltd / SETI), R. Maddalena (Green Bank Observatory), D. DeBoer (SETI / UCB), B. Diamond (SETI), J. Tarter (SETI), J. Welch (SETI / UCB), T. Koumrian (SETI), C. Shumaker (SETI), M. Masters (SETI), M. Fleming (Minex Engineering Corp.), G. Singh (SETI)
on 4 Jun 2021; 00:15 UT
Credential Certification: Wael Farah (wfarah@seti.org)
Subjects: Radio, Fast Radio Burst
We report the detection of a bright double-peaked radio burst from the repeating source FRB20201124A using the Allen Telescope Array (ATA). The ATA has been undergoing a refurbishment program aimed at upgrading the telescope feeds and the digital signal processing system to improve the sensitivity and capability of the instrument. This discovery marks the first FRB detection with this nascent system.
For these observations, nine of the 42, 6.1-m, dishes were tuned to a spectral band centered at 1.5 GHz, with an effective bandwidth of 720 MHz. Dual-polarisation data from the antennas were split into 2880 frequency channels each 0.25 MHz wide each, and detected and integrated to a time resolution of 480 microseconds. The data from the 9 dual-polarization signals were then incoherently summed and processed using the GPU-accelerated dedispersion algorithm, HEIMDALL (Barsdell 2012). FRB-candidate plots were generated and subjected to human scrutiny.
The time of arrival of the first peak, at the highest frequency, is 2021-05-18-01:26:11.9 UTC, and the two peaks are roughly separated by 10 ms. The dispersion measure of the first component, as reported by HEIMDALL is 411.72 pc cm^{-3}. We estimate the temporal widths of the first and second components at 2.8 ms and 1.9 ms, respectively. The signal-to-noise ratio (S/N) of the first component measured across the 200 MHz band where the emission is brightest is ~20, giving a preliminary fluence estimate of 120 Jy-ms. The measured S/N of the second peak is 10, and an estimate of its fluence is 45 Jy-ms.
A waterfall plot and and a dedispersed time series can be found here.
