[vsnet-grb-info 18962] GRB 170115B: AstroSat CZTI (Veto) detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20466
SUBJECT: GRB 170115B:  AstroSat  CZTI (Veto)  detection
DATE:    17/01/16 07:35:52 GMT
FROM:    Vidushi Sharma at IUCAA  <vidushi at iucaa.in>

V. Sharma, V. Bhalerao 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 GRB170115B (Fermi detection: R. Hamburg et al., GCN Circ. 20463) in the 40-200 keV energy range. The light curve shows multiple peaks structure with main peak at 17:49:14.03 UT, coincident with Fermi trigger. The measured peak count rate is 618.7 counts/sec above the background in combined data of four quadrants, with a total of 4196.9 counts. The local mean background count rate was 372.3 counts/sec. Using cumulative rates, we measure a T90 of 15.3 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.