[vsnet-grb-info 19516] GRB 170614A: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21256
SUBJECT: GRB 170614A: AstroSat CZTI detection
DATE:    17/06/19 10:49:18 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi at 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-duration GRB 170614A, which was also detected by Fermi-GBM (trigger #519133191), INTEGRAL SPI-ACS (trigger #7869), Konus-Wind (trigger time on 11:39:55.892) and CALET (Takahashi et al, GCN 21255).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks emission with the strongest peak at 11:40:04.89 UT, ~21 s after the CALET Trigger. The measured peak count rate is 593.1 cts/s above the background in combined data of four quadrants, with a total of 5775 cts. The local mean background count rate was 369.9 cts/s. Using cumulative rates, we measure a T90 of 21.4 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.