[vsnet-grb-info 20746] GRB 180620B: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22844
SUBJECT: GRB 180620B: AstroSat CZTI detection
DATE:    18/06/25 15:56:59 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi at iucaa.in>

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 180620B, which was also detected by Swift (Evans P. A. et al., GCN 22807), Fermi-GBM (Mailyan B. et al., GCN 22813), Konus-Wind (Svinkin D. et al., GCN 22825).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 15:50:37.5 UT. The measured peak count rate is 259.6 cts/s above the background in combined data of four quadrants, with a total of 2643 cts. The local mean background count rate was 582.3 cts/s. Using cumulative rates, we measure a T90 of 22.3 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.