TITLE:   GCN CIRCULAR
NUMBER:  27492
SUBJECT: GRB 200403A: AstroSat CZTI detection
DATE:    20/04/04 14:12:59 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, 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 200403A, which was also detected by Fermi GBM Final Real-time (GCN #27482) and Global MASTER-Net (Lipunov V. et al., GCN #27490) . 

The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-04-03 21:30:16 UT. The measured peak count rate associated with the burst is 220 +/- 18.3 cts/s above the background in the combined data of four quadrants, with a total of 2564 +/- 50.1 cts. The local mean background count rate was 578 +/- 1.2 cts/s. Using cumulative rates, we measure a T90 of 25.5 +/- 1.08 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.