GCN Circular 30968
Subject
GRB 211022A: AstroSat CZTI detection
Date
2021-10-24T07:45:11Z (3 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.,
2021, JApA, 42, 73) showed detection of a long GRB 211022A, which was
also detected by GECAM (Zhao et al., GCN 30955).
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
2021-10-22 00:48:52.0 UT. The measured peak count rate associated with
the burst is 166 (+14, -13) cts/s above the background in the combined
data of four quadrants, with a total of 11186 (+925, -981) cts. The
local mean background count rate was 598 (+1, -1) cts/s. Using
cumulative rates, we measure a T90 of 92 (+63, -9) 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 2021-10-22 00:48:54.1 UT. The
measured peak count rate is 2130 (+71, -86) cts/s above the background
in the combined Veto data of four quadrants, with a total of 159488
(+3241, -5602) cts. The local mean background count rate was 21425 (+3,
-91) cts/s. We measure a T90 of 119 (+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 [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