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GCN Circular 31076

Subject
GRB 211110A: AstroSat CZTI detection
Date
2021-11-11T14:22:57Z (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 211110A, which was
also detected by GECAM (S. L. Xie et al., GCN 31074).

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
2021-11-10 03:26:29.0 UT. The measured peak count rate associated with
the burst is 59 (+23, -8) cts/s above the background in the combined
data of two quadrants, with a total of 529 (+170, -154) cts. The local
mean background count rate was 230 (+1, -2) cts/s. Using cumulative
rates, we measure a T90 of 14 (+6, -6) 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 2021-11-10 03:26:22.54 UT. The
measured peak count rate is 257 (+72, -44) cts/s above the background in
the combined Veto data of four quadrants, with a total of 1442 (+426,
-393) cts. The local mean background count rate was 1530 (+5, -6) cts/s.
We measure a T90 of 14 (+4, -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
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