TITLE:   GCN CIRCULAR
NUMBER:  22842
SUBJECT: GRB 180618A: AstroSat CZTI detection
DATE:    18/06/25 13:49:11 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 short GRB 180618A, which was also detected by  Swift (LaPorte S. J. et al., GCN 22790), Fermi-GBM (Hamburg R. et al., GCN 22794), Konus-Wind (Svinkin D. et al., GCN 22822).

The source was clearly detected in the 40-200 keV energy range. The light curve shows a single peak of emission with peak at 00:43:13.5 UT. The measured peak count rate is 217.1 cts/s above the background in combined data of four quadrants, with a total of 140.9 cts. The local mean background count rate was 456.9 cts/s. Using cumulative rates, we measure a T90 of 2.1 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.