TITLE:   GCN CIRCULAR
NUMBER:  32231
SUBJECT: GRB 220619A: AstroSat CZTI detection
DATE:    22/06/20 04:59:25 GMT
FROM:    Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>

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 220619A which was 
also detected by Fermi GBM (TrigNum: 677307509).

The source was clearly detected in the 20-200 keV energy range. The 
light curve peaks at 2022-06-19 04:58:41.500 UTC. The measured peak 
count rate associated with the burst is 139 (+37, -18) counts/s above 
the background in the combined data of three (out of four) quadrants, 
with a total of 2456 (+577, -573) counts. The local mean background 
count rate was 320 (+2, -3) counts/s. Using cumulative rates, we measure 
a T90 of 47 (+20, -15) s.

It was also clearly detected in the CsI anticoincidence (Veto) detector 
in the 100-500 keV energy range. The light curve peaks at 2022-06-19 
04:58:42.035 UTC. The measured peak count rate is 333 (+70, -39) 
counts/s above the background in the combined Veto data of all 
quadrants, with a total of 6930 (+826, -1099) counts. The local mean 
background count rate was 1405 (+3, -3) counts/s. We measure a T90 of 55 
(+15, -18) 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.