[vsnet-grb-info 22705] GRB 190609A: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24804
SUBJECT: GRB 190609A: AstroSat CZTI detection
DATE:    19/06/13 09:39:49 GMT
FROM:    Prachee Ghumatkar at IUCAA/AstroSat  <prachee at iucaa.in>

P. Ghumatkar, V. Sharma, D. Bhattacharya, T. Khanam and A. Vibhute (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 long GRB 190609A, which was also detected by Fermi GBM (GCN #24773) and BALROG (Burgess J. et al., GCN #24774).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple pulses of emission with the strongest peak at 07:34:44.5 UT. The measured peak count rate associated with the burst is 555 cts/s above the background in the combined data of four quadrants, with a total of 7392 cts. The local mean background count rate was 521 cts/s. Using cumulative rates, we measure a T90 of 40.1 s. In preliminary analysis, we find that 550 Compton events are associated with this event.

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.