[vsnet-grb-info 26897] GRB 201207A: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29000
SUBJECT: GRB 201207A: AstroSat CZTI detection
DATE:    20/12/08 08:42:24 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya at iucaa>

S. Gupta, P. Sawant, 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 detection of a bright long GRB 201207A, which was also detected by Fermi GBM Final Real-time (GCN #28996) and Global MASTER-Net (Lipunov V. et al., GCN #28997).

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 2020-12-07 23:27:02.669 UT. The measured peak count rate associated with the burst is 283 +/- 24 cts/s above the background in the combined data of four quadrants, with a total of 2494 +/- 34 cts. The local mean background count rate was  509 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 18.3 +/- 0.4 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-12-07 23:27:01.628 UT. The measured peak count rate is 820 +/- 40 cts/s above the background in the combined Veto data of four quadrants, with a total of 5754 +/- 46 cts. The local mean background count rate was 1467 +/- 1  cts/s. We measure a T90 of 19.6 +/- 0.3 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.