[vsnet-grb-info 25530] GRB 200422A: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27630
SUBJECT: GRB 200422A: AstroSat CZTI detection
DATE:    20/04/23 09:23:31 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya at iucaa>

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 200422A, which was also detected by  IPN (Hurley K. et al., GCN #27626) and Global MASTER-Net (Lipunov V. et al., GCN #27628).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 2020-04-22 07:22:15.088 UT. The measured peak count rate associated with the burst is 2864 +/- 56 cts/s above the background in the combined data of four quadrants, with a total of 29362 +/- 55 cts. The local mean background count rate was 566 +/- 2 cts/s. Using cumulative rates, we measure a T90 of 20.46 +/- 0.007 s. In preliminary analysis, we find that 2853 Compton events are associated with this event.

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.