GCN Circular 28288

S. Gupta, V. Sharma, A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a bright short GRB 200826A, which was also detected by Fermi GBM (GCN #28284), Global MASTER-Net (Lipunov V. et al., GCN #28285) and BALROG (Kunzweiler F. et al., GCN #28286).

The source was clearly detected in the 40-200 keV energy range. The light curve showed a single peak of emission peaking at 2020-08-26 04:29:51.529 UT. The measured peak count rate associated with the burst is 686 +/- 34 cts/s above the background in the combined data of four quadrants, with a total of 1383 +/- 10 cts. The local mean background count rate was 537 +/- 2 cts/s. Using cumulative rates, we measure a T90 of 1.95 +/- 0.01 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed a single peak of emission peaking at 2020-08-26 04:29:51.000 UT. The measured peak count rate is 735 +/- 53 cts/s above the background in the combined Veto data of four quadrants, with a total of 1043 +/- 42 cts. The local mean background count rate was 1870 +/- 16 cts/s.  We measure a T90 of 2.17 +/- 0.23 s from the cumulative Veto light curve.

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.