16th of November 2018 |
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An MWA search for counterparts to ASKAP FRBs |
by Sokolowski et al. |
Sokolowski et al. have presented the results of a coordinated campaign
conducted with the Murchison Widefield Array (MWA) to shadow fast
radio bursts (FRBs) detected by the Australian Square Kilometre Array
Pathfinder (ASKAP) at 1.4 GHz. The campaign resulted in simultaneous
MWA observations of seven ASKAP FRBs, however no counterparts were
found in 170–200 MHz band MWA images taken at 0.5 s time resolution.
The limits show that pulse broadening alone cannot explain the
non-detections, and that there must be a spectral turnover at
frequencies above 200 MHz.
The image above illustrates the MWA shadowing strategy for FRB 180324 on top of the image by Haslam et al. 1982 at 408 MHz). The large (approximately 7 degree) red circles represent coverage of ASKAP antenna beams the small white circles (1.2 degrees across) are the individual beams of an ASKAP antenna, with the detection of FRB 180324 shown as a yellow star. The green (at 0.5 and 0.1) and white-dashed (at 0.001 with angular size 42 degree × 42 degree) contours show the MWA beam normalized to maximum response at zenith. Full results are published in the Astrophysical Journal |