[vsnet-grb-info 18213] GRB 1600623A: Astrosat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19661
SUBJECT: GRB 1600623A: Astrosat CZTI detection
DATE:    16/07/06 06:58:47 GMT
FROM:    Varun Bhalerao at IUCAA  <varunb at iucaa.in>

V. Bhalerao (IUCAA), V. Kumar (IUCAA), D. Bhattacharya (IUCAA), A. R. Rao (TIFR), S. Vadawale (PRL)  report on behalf of the Astrosat CZTI collaboration:

 Analysis of Astrosat data showed the detection of very bright GRB 1600623A (Fermi-LAT detection: Vianello et al., GCN 19553, Mailyan et al., GCN 19555; Mingo et al. GCN 19558; Frederiks et al. GCN 19554)

The source was clearly detected in the 40-200 keV energy range. The light curve shows a single peak at UT 04:59:45.0, 49.23 seconds before the fermi trigger At 05:00:34.23 (trigger 488350837 / 160623209). The peak count rate was 2940 counts/sec above the background (four quadrants summed together), with a total of 20385 counts.  The local mean background count rate of 193.2 is counts/sec.  Using cumulative rates, we measure a T90 of 14.2 sec.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=node/9 . 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.