GCN Circular 32183
Subject
GRB 220608A: AstroSat CZTI detection
Date
2022-06-09T03:23:52Z (2 years ago)
From
Gaurav Waratkar at IIT,Bombay <gauravwaratkar@iitb.ac.in>
R. Gopalakrishnan (IUCAA), V. Prasad (IUCAA), G. Waratkar (IITB), A.
Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka
University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report
on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al.,
2021, JApA, 42, 73) showed detection of a long GRB 220608A which was
also reported by Fermi GBM (GCN 32178).
The source was clearly detected in the 20-200 keV energy range. The
light curve showed multiple peaks of emission with the strongest peak at
2022-06-08 05:03:45.50 UTC. The measured peak count rate associated with
the burst is 294 (+43, -35) counts/s above the background in the
combined data of three quadrants, with a total of 2720 (+389, -365)
counts. The local mean background count rate was 393 (+1, -2) counts/s.
Using cumulative rates, we measure a T90 of 36 (+11, -3) s.
It was also clearly detected in the CsI anticoincidence (Veto) detector
in the 100-500 keV energy range. The light curve showed multiple peaks
of emission with the strongest peak at 2022-06-08 05:03:44.45 UTC. The
measured peak count rate is 483 (+71, -70) counts/s above the background
in the combined Veto data of four quadrants, with a total of 4040 (+617,
-645) counts. The local mean background count rate was 1621 (+4, -4)
counts/s. We measure a T90 of 36 (+5, -10) s from the cumulative Veto
light curve.
CZTI GRB detections are reported regularly on the payload site at
http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led
consortium of institutes across India, including VSSC, URSC, IUCAA, SAC,
and PRL. The Indian Space Research Organisation funded, managed, and
facilitated the project.