TITLE:   GCN CIRCULAR
NUMBER:  23102
SUBJECT: GRB 180728A: AstroSat CZTI detection
DATE:    18/08/09 11:23:16 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 long GRB 180728A, which was also detected by Swift (Starling R. L. C. et al., GCN 23046), Fermi-GBM (Veres P. et al., GCN 23053) and Konus-Wind (Frederiks D. et al., GCN 23061).

The source was clearly detected in the 40-200 keV energy range. The light curve shows a single peak of emission with peak at 17:29:13.50 UT. The measured peak count rate is 1849.2 cts/s above the background in combined data of four quadrants, with a total of 6236 cts. The local mean background count rate was 650.8 cts/s. Using cumulative rates, we measure a T90 of 13.4 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. 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.