Back

GCN Circular 21702

Subject

GRB 170822A: AstroSat CZTI detection

Date

2017-08-25T19:15:22Z (7 years ago)

From

Vidushi Sharma at IUCAA <vidushi@iucaa.in>

V. Sharma (IUCAA), V. Bhalerao (IITB), 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 short GRB 170822A (Swift detection: Melandri A. et al, GCN Circ. 21640Not found
 
 
) in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 09:11:52.0 UT, around 1 s after the Swift/BAT trigger. The measured peak count rate is 163.1 counts/s above the background in combined data of four quadrants, with a total 369 counts. The local mean background count rate was 399.0 counts/s. Using cumulative rates, we measure a T90 of 62.3 s.

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.