[vsnet-grb-info 19160] GRB 170228A: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20788
SUBJECT: GRB 170228A: AstroSat CZTI detection
DATE:    17/03/01 18:14:23 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi at iucaa.in>

V. Sharma, V. Bhalerao (IITB) and 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 clear detection of GRB170228A (Fermi-LAT detection: E. Bissaldi et al., GCN Circ. 20785) in the 40-200 keV energy range. The light curve shows single peak structure with main peak at 19:03:02.71 UT, 2 s after the Fermi trigger. The measured peak count rate is 541.9 counts/sec above the background in combined data of four quadrants, with a total 3569 counts. The local mean background count rate was 349.1 counts/s. Using cumulative rates, we measure a T90 of 14.1 s.

It was clearly detected in the CsI anticoincidence detector (Veto) also as bright detection 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.