[vsnet-grb-info 24469] GRB 191220.59: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26568
SUBJECT: GRB 191220.59: AstroSat CZTI detection
DATE:    19/12/23 11:43:11 GMT
FROM:    Ramkrishna Gaikwad at IUCAA/AstroSat  <ramkrishna at iucaa.in>

R. Gaikwad, 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 GRB 191220.59, which was also detected by Global MASTER-Net (Lipunov V. et al., GCN #26523).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peak of emission with strongest peak at 2019-12-20 14:08:29.0 UT. The measured peak count rate associated with the burst is 147 cts/s above the background in the combined data of four quadrants, with a total of 2877 cts. The local mean background count rate was 513 cts/s. Using cumulative rates, we measure a T90 of 72.99 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.