[vsnet-grb-info 28452] GRB 210730A: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30555
SUBJECT: GRB 210730A: AstroSat CZTI detection
DATE:    21/07/30 17:16:49 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 the detection of a long GRB 210730A,
which was also detected by Swift-BAT (Sonbas et al., GCN 30548, Sakamoto
et al., GCN 30554) and Swift-XRT (Beardmore et al., GCN 30550).

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
2021-07-30 04:57:28.55 UT. The measured peak count rate associated with
the burst is 502 (+181, -71) cts/s above the background in the combined
data of four quadrants, with a total of 621 (+161, -206) cts. The local
mean background count rate was 508 (+12, -11) cts/s. Using cumulative
rates, we measure a T90 of 3.3 (+1.1, -1.9) 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