GCN Circular 32336

A. Suresh (IITB), 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 the detection of a long GRB 220702B which was 
also detected by Fermi-GBM (Fermi GBM Team, GCN 32324
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 ).

The source was clearly detected in the 20-200 keV energy range. The 
light curve peaks at 2022-07-02 20:12:46.500 UTC. The measured peak 
count rate associated with the burst is 117 (+47 -12) counts/s above the 
background in the combined data of all four quadrants, with a total of 
988 (+222 -248) counts. The local mean background count rate was 474 (+4 
-5) counts/s. Using cumulative rates, we measure a T90 of 16 (+1 -4) 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 2022-07-02 20:12:47.671 UTC. The 
measured peak count rate is 208 (+67 -40) counts/s above the background 
in the combined Veto data of all quadrants, with a total of 1533 (+352 
-382) counts. The local mean background count rate was 1405 (+5 -6) 
counts/s. We measure a T90 of 18 (+1 -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. 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.