GCN Circular 32140
Subject
GRB 220527A: AstroSat CZTI detection
Date
2022-05-28T05:23:18Z (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 220527A which was
also reported by AGILE (Ursi et al. GCN 32129), Fermi-GBM (GCN 32130),
Fermi-LAT (Bissaldi et al., GCN 32131), Swift-XRT (Sbarufatti et al.,
GCN 32135), Swift-UVOT (Tohuvavohu et al., GCN 32136) and CALET (Yamaoka
et al., GCN 32139).
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
2022-05-27 09:17:23.55 UTC. The measured peak count rate associated with
the burst is 1879 (+251, -171) counts/s above the background in the
combined data of four quadrants, with a total of 5318 (+224, -235)
counts. The local mean background count rate was 496 (+4, -5) counts/s.
Using cumulative rates, we measure a T90 of 7 (+1, -1) 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 2022-05-27 09:17:19.39 UTC. The
measured peak count rate is 1880 (+96, -93) counts/s above the
background in the combined Veto data of four quadrants, with a total of
11483 (+534, -559) counts. The local mean background count rate was 1644
(+6, -6) counts/s. We measure a T90 of 14 (+3, -2) 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 [1]. 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.
Links:
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[1] http://astrosat.iucaa.in/czti/?q=grb