[vsnet-grb-info 19019] GRB 170127C: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20561
SUBJECT: GRB 170127C: AstroSat CZTI detection
DATE:    17/01/28 17:45:19 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi at iucaa.in>

V. Sharma, D. Bhattacharya and V. Bhalerao (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 GRB170127C (Fermi detection: E. Bissaldi et al., GCN Circ. 20543) in the 40-200 keV energy range. The light curve shows single peak structure with main peak at 01:35:47.79 UT, coincident with Fermi trigger. The measured peak count rate is 895.2 counts/sec above the background in combined data of four quadrants, with a total 904.3 counts. The local mean background count rate was 416.8 counts/sec. Using cumulative rates, we measure a T90 of 0.91 secs.

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.