TITLE:   GCN CIRCULAR
NUMBER:  28695
SUBJECT: GRB 201019B: AstroSat CZTI detection
DATE:    20/10/20 05:00:27 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma 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 long GRB 201019B, which was also detected by Fermi GBM Final Real-time (GCN #28687).

The source was clearly detected in the 40-200 keV energy range. The light curve showed a single peak of emission peaking at 2020-10-19 01:40:11.077 UT. The measured peak count rate associated with the burst is 167 +/- 18 cts/s above the background in the combined data of four quadrants, with a total of 1104 +/- 17 cts. The local mean background count rate was  400 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 14.74 +/- 0.14 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 2020-10-19 01:40:09.503 UT. The measured peak count rate is 276 +/- 33 cts/s above the background in the combined Veto data of four quadrants, with a total of 1552 +/- 36 cts. The local mean background count rate was 1540 +/- 2  cts/s. We measure a T90 of 14.46 +/- 1.62 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.