GCN Circular 22645
Subject
GRB 180404B: AstroSat CZTI detection
Date
2018-04-16T17:52:13Z (6 years ago)
From
Vidushi Sharma at IUCAA <vidushi@iucaa.in>
V. Sharma (IUCAA), V. Bhalerao (IIT-B), D. Bhattacharya (IUCAA), 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 180404B, which was also detected by Swift (Palmer D. et al., GCN 22590), Fermi-GBM (Kienlin A. V. et al., GCN 22597) and Konus-Wind (Svinkin D. et al., GCN 22609).
The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 02:11:53.5 UT, ~9.5 s after the Swift trigger. The measured peak count rate is 281.6 cts/s above the background in combined data of four quadrants, with a total of 3662 cts. The local mean background count rate was 541 cts/s. Using cumulative rates, we measure a T90 of 44 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.