TITLE:   GCN CIRCULAR
NUMBER:  23099
SUBJECT: GRB 180723A: AstroSat CZTI detection
DATE:    18/08/08 07:57:10 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi@iucaa.in>

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

Analysis of Astrosat CZTI data showed the detection of a bright GRB 180723A, which was also detected by CALET (Ishizaki W. et al., GCN 23029) and Fermi-GBM (Poolakkil S. et al., GCN 23035).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 18:09:49.50 UT. The measured peak count rate is 1123.5 cts/s above the background in combined data of four quadrants, with a total of 6717 cts. The local mean background count rate was 543.5 cts/s. Using cumulative rates, we measure a T90 of 25.3 s. In preliminary analysis, we find that 459 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.

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.