GCN Circular 30737
Subject
GRB 210826A: AstroSat CZTI detection
Date
2021-08-28T14:30:28Z (4 years ago)
From
Gaurav Waratkar at IIT,Bombay <gauravwaratkar@iitb.ac.in>
V. Prasad (IUCAA), P. Sawant (IUCAA), G. Waratkar (IITB), A. Vibhute
(IUCAA), V. Bhalerao (IITB), D. Bhattacharya (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,
2020, arxiv:2011.07067) showed detection of a long GRB 210826A, which
was also detected by Fermi-GBM (trigger no. 210826293, GCN 30716) and
Fermi-LAT (Ohno et al., GCN 30721).
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
2021-08-26 07:01:53.50 UT. The measured peak count rate associated with
the burst is 183 (+45, -24) cts/s above the background in the combined
data of four quadrants, with a total of 2161 (+327, -549) cts. The local
mean background count rate was 560 (+4, -2) cts/s. Using cumulative
rates, we measure a T90 of 24 (+17, -10) s.
It was also 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 2021-08-26 07:01:47.03 UT. The
measured peak count rate is 200 (+95, -5) cts/s above the background in
the combined Veto data of four quadrants, with a total of 1953 (+648,
-720) cts. The local mean background count rate was 1907 (+6, -6) cts/s.
We measure a T90 of 14 (+8, -5) 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, ISAC, 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