GCN Circular 32618
Subject
GRB 220921A: ATCA detection of radio counterpart
Event
Date
2022-10-03T06:49:53Z (4 years ago)
From
James Leung at U of Sydney/VAST <jleu9465@uni.sydney.edu.au>
James Leung (University of Sydney/CSIRO), Ziteng Wang (University of
Sydney/CSIRO), Emil Lenc (CSIRO), Tara Murphy (University of Sydney)
The Australia Telescope Compact Array (ATCA) observed GRB 220921A
(Pillera et al., GCN 32568) at multiple frequencies starting on 2022
September 28, from 16:30 to 21:00 UTC (7.2 to 7.4d post-trigger).
We detect a radio source in all bands at the position:
RA (J2000) = 04:25:53.4
Dec (J2000) = -40:24:20.5
with uncertainty ~0.5" in each coordinate, which is consistent with
the MASTER optical (Lipunov et al., GCN 32570) and ALMA mm (Laskar
et al., GCN 32577) candidate afterglow positions.
We report our preliminary flux density measurements below:
Freq (GHz) | Peak Flux Density (micro-Jy/beam)
----------------------------------------------
5.5 | 163 +/- 19
9.0 | 364 +/- 17
16.7 | 763 +/- 50
21.2 | 988 +/- 95
Ongoing observations are planned.
We thank CSIRO staff for rapidly scheduling and supporting these
observations.