TITLE:   GCN CIRCULAR
NUMBER:  25287
SUBJECT: GRB 190805B: AstroSat CZTI detection
DATE:    19/08/08 11:27:52 GMT
FROM:    Prachee Ghumatkar at IUCAA/AstroSat  <prachee@iucaa.in>

P. Ghumatkar, V. Sharma and D. Bhattacharya and A. Vibhute (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 190805B, which was also detected by Fermi GBM Final Real-time Localization (GCN #25270), MAXI/GSC detection (Sato T. et al., GCN #25271), BALROG localization (Biltzinger B. et al., GCN #25272), Tiled Swift observations (Evans P. A. et al., GCN #25275), Fermi GBM detection (Hamburg R. et al., GCN #25277), Swift-XRT (Perri M. et al., GCN #25279) and Konus-Wind (Kozlova A. et al., GCN #25285).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple pulses of emission with the strongest peak at 04:46:05.0 UT. The measured peak count rate associated with the burst is 323 cts/s above the background in the combined data of four quadrants, with a total of 4289 cts. The local mean background count rate was 588 cts/s. Using cumulative rates, we measure a T90 of 24 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.