[vsnet-grb-info 18987] GRB 170121B: AstroSat CZTI detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20511
SUBJECT: GRB 170121B:  AstroSat CZTI detection
DATE:    17/01/23 17:18:36 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 GRB170121B (Fermi GBM detection: R.Hamburg et al., GCN Circ. 20505) in the 40-200 keV energy range. The light curve shows two peaks structure with brightest peak at 14:44:31.41 UT, 9 seconds after the Fermi trigger. The measured peak count rate is 320.2 counts/sec above the background in combined data of four quadrants, with a total of 4185.9 counts. The local mean background count rate was 344.2 counts/sec. Using cumulative rates, we measure a T90 of 28.3 secs.

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.