TITLE:   GCN CIRCULAR
NUMBER:  26610
SUBJECT: GRB 191225A : AstroSat CZTI detection
DATE:    19/12/29 09:13:02 GMT
FROM:    Ramkrishna Gaikwad at IUCAA/AstroSat  <ramkrishna@iucaa.in>

R. Gaikwad, S. Gupta, V. Sharma and D. Bhattacharya (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 GRB 191225A, which was also detected by Fermi GBM Final Real-time Localization ( GCN #26579).

The source was clearly detected in the 40-200 keV energy range. The light curve shows a single peak of emission  peaking at 2019-12-25 07:25:16.0 UT. The measured peak count rate associated with the burst is 241 cts/s above the background in the combined data of four quadrants, with a total of 435 cts. The local mean background count rate was 545 cts/s. Using cumulative rates, we measure a T90 of 6.9 s.

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.