GCN Circular 27563

S. Gupta, V. Sharma, A. Vibhute 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 200412B, which was also detected by Fermi GBM Final Real-time (GCN #27547), BALROG (Burgess J. et al., GCN #27548), Global MASTER-Net (Lipunov V. et al, GCN #27549), Tiled Swift (Evans P. et al., GCN #27551), Fermi-LAT (Longo F. et al., GCN #27557), Fermi GBM (Mailyan B. et al., GCN #27558) and Swift-XRT (Page K. et al., GCN #27561). 

The source was clearly detected in the 40-200 keV energy range. The light curve shows a single peak of emission peaking at 2020-04-12 09:08:49.5 UT. The measured peak count rate associated with the burst is 1160 +/- 40.72 cts/s above the background in the combined data of four quadrants, with a total of 3452 +/- 16.55 cts. The local mean background count rate was 519 +/- 0.87 cts/s. Using cumulative rates, we measure a T90 of 7.17 +/- 0.06 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.