TITLE:   GCN CIRCULAR
NUMBER:  35173
SUBJECT: GRB 231123A: AstroSat CZTI detection
DATE:    23/11/24 07:55:13 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>

P. K. Navaneeth (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a faint GRB 231123A which was also detected by Fermi-GBM (Fermi GBM team, GCN Circ. 35162).

We see a faint detection in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2023-11-23 02:44:04.5 UTC. The measured peak count rate associated with the burst is 173 (+82, -43) counts/s above the background in the combined data of three quadrants (out of four), with a total of 203 (+97, -93) counts. The local mean background count rate was 272 (+4, -6) counts/s. Using cumulative rates, we measure a T90 of 3.5 (+1.5, -2.3) s.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb