TITLE: GCN CIRCULAR NUMBER: 30968 SUBJECT: GRB 211022A: AstroSat CZTI detection DATE: 21/10/24 07:45:11 GMT FROM: Gaurav Waratkar at IIT,Bombay <gauravwaratkar@iitb.ac.in> V. Prasad (IUCAA), P. Sawant (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (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 detection of a long GRB 211022A, which was also detected by GECAM (Zhao et al., GCN 30955). The source was clearly detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2021-10-22 00:48:52.0 UT. The measured peak count rate associated with the burst is 166 (+14, -13) cts/s above the background in the combined data of four quadrants, with a total of 11186 (+925, -981) cts. The local mean background count rate was 598 (+1, -1) cts/s. Using cumulative rates, we measure a T90 of 92 (+63, -9) s. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2021-10-22 00:48:54.1 UT. The measured peak count rate is 2130 (+71, -86) cts/s above the background in the combined Veto data of four quadrants, with a total of 159488 (+3241, -5602) cts. The local mean background count rate was 21425 (+3, -91) cts/s. We measure a T90 of 119 (+5, -10) s from the cumulative Veto light curve. CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb [1]. 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. Links: ------ [1] http://astrosat.iucaa.in/czti/?q=grb