[vsnet-grb-info 28343] GRB 210709A: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30446
SUBJECT: GRB 210709A: AstroSat CZTI detection
DATE:    21/07/12 04:44:57 GMT
FROM:    Gaurav Waratkar at IIT,Bombay  <gauravwaratkar at 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,
2020, arxiv:2011.07067) showed detection of a long GRB 210709A, which
was also detected by Fermi-GBM (GCN 30427).

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
2021-07-09 04:49:04.5 UT. The measured peak count rate associated with
the burst is 201 (+40, -42) cts/s above the background in the combined
data of four quadrants, with a total of 909 (+221, -239) cts. The local
mean background count rate was 386 (+4, -4) cts/s. Using cumulative
rates, we measure a T90 of 14 (+4, -4) s. 

It was also 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