GCN Circular 22103

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 bright GRB 171103A, which was also detected by Swift-BAT (Ukwatta T. N. et al, GCN # 22095), Fermi-GBM (Veres P., GCN # 22100) and Konus-Wind (Tsvetkova A. et al, GCN # 22101).

The source was clearly detected in the 40-200 keV energy range. The light curve shows single peak of emission with peak at 23:10:32.100 UT. The measured peak count rate is 1420.9 cts/s above the background in combined data of four quadrants, with a total of 2964 cts. The local mean background count rate was 349.1 cts/s. Using cumulative rates, we measure a T90 of 0.46 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.