TITLE:   GCN CIRCULAR
NUMBER:  30223
SUBJECT: GRB 210607C: AstroSat CZTI detection
DATE:    21/06/12 14:03:23 GMT
FROM:    Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>

 P. Sawant (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), S. Gupta
(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,
2020, arxiv:2011.07067) showed detection of a long GRB 210607C, which
was also detected by Insight-HXMT/HE (GCN #30202). 

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
2021-06-07 21:39:21.5 UT. The measured peak count rate associated with
the burst is 2757 (+90, -98) cts/s above the background in the combined
data of four quadrants, with a total of 22768 (+388, -416) cts. The
local mean background count rate was 469 (+3, -3) cts/s. Using
cumulative rates, we measure a T90 of 18 (+1, -1) 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 2021-06-07 21:39:20.1 UT. The
measured peak count rate is 2596 (+99, -112) cts/s above the background
in the combined Veto data of four quadrants, with a total of 18010
(+525, -559) cts. The local mean background count rate was 1507 (+5, -6)
cts/s. We measure a T90 of 14 (+1, -1) 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, ISAC, IUCAA, SAC
and PRL. The Indian Space Research Organisation funded, managed and
facilitated the project.