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GCN Circular 31099

GRB 211118A: AstroSat CZTI detection
2021-11-20T18:21:36Z (3 years ago)
Gaurav Waratkar at IIT,Bombay <>
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 GRB 211118A, which was also
detected by Swift/BAT-GUANO (Raman et al., GCN 31096).

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
2021-11-18 23:38:13.65 UT. The measured peak count rate associated with
the burst is 915 (+217, -92) cts/s above the background in the combined
data of two quadrants, with a total of 806 (+94, -109) cts. The local
mean background count rate was 446 (+7, -8) cts/s. Using cumulative
rates, we measure a T90 of 2.2 (+0.6, -0.4) s.

It was also clearly detected in the CsI anticoincidence (Veto) detector
in the 100-500 keV energy range. 

CZTI GRB detections are reported regularly on the payload site at [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.


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