TITLE:   GCN CIRCULAR
NUMBER:  30098
SUBJECT: GRB 210528A: AstroSat CZTI detection
DATE:    21/05/29 14:46:52 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 short GRB 210528A, which
was also detected by Fermi-GBM (GCN #30090).

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
2021-05-28 14:03:45.5 UT. The measured peak count rate associated with
the burst is 682 (+186, -164) cts/s above the background in the combined
data of all four quadrants, with a total of 307 (+69, -65) cts. The
local mean background count rate was 547 (+9, -11) cts/s. Using
cumulative rates, we measure a T90 of 0.89 (+0.2, -0.3) 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
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