TITLE:   GCN CIRCULAR
NUMBER:  34376
SUBJECT: GRB 230805B: AstroSat CZTI detection
DATE:    23/08/09 15:43:08 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 long GRB 230805B which was also detected by Swift-BAT (Cenko et al., GCN Circ. 34339), and Fermi-GBM (Mangan et al., GCN Circ. 34357).

The source was detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2023-08-05 11:23:33.50 UTC. The measured peak count rate associated with the burst is 165 (+36, -38) counts/s above the background in the combined data of three quadrants (out of four), with a total of 1304 (+507, -508) counts. The local mean background count rate was 337 (+1, -2) counts/s. Using cumulative rates, we measure a T90 of 54 (+27, -25) s. 

The source was also detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

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