[vsnet-grb-info 26017] GRB 200716A: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  28117
SUBJECT: GRB 200716A: AstroSat CZTI detection
DATE:    20/07/16 16:53:57 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya at iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 200716A, which was also detected by Fermi GBM (GCN #28109), BALROG (Biltzinge B. et al., GCN #28112) and AGILE (Ursi A. et al., GCN #28116).

The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-07-16 01:27:08.646 UT. The measured peak count rate associated with the burst is 641 +/- 30 cts/s above the background in the combined data of four quadrants, with a total of 5950 +/- 52 cts. The local mean background count rate was 480 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 44.029 +/- 0.032 s. In preliminary analysis, we find that 637 Compton events are associated with this event.

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 2020-07-16 01:27:07.277 UT. The measured peak count rate is 641 +/- 30 cts/s above the background in the combined Veto data of four quadrants, with a total of 6218 +/- 72 cts. The local mean background count rate was 1442 +/- 1.4 cts/s.  We measure a T90 of 43.651 +/- 0.024 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.