[vsnet-grb-info 20915] GRB 180715B: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23013
SUBJECT: GRB 180715B: AstroSat CZTI detection
DATE:    18/07/22 15:04:34 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi at iucaa.in>

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 short GRB 180715B, which was also detected by Fermi-GBM (trigger # 553369644, 17:47:19.090 UT) and Zwicky Transient Facility (Cenko S. B. et al., GCN 22969)

The source was clearly detected in the 40-200 keV energy range. The light curve shows a single peak of emission with peak at 17:47:19.5 UT, ~4 s after the GBM trigger. The measured peak count rate is 412.5 cts/s above the background in combined data of four quadrants, with a total of 604 cts. The local mean background count rate was 540.5 cts/s. Using cumulative rates, we measure a T90 of 1.7 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.