{
  "bibcode": "2021GCN.30693....1P",
  "body": "V. Prasad (IUCAA), P. Sawant (IUCAA), G. Waratkar (IITB), A. Vibhute\n(IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao\n(IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat\nCZTI collaboration:\n\nAnalysis of AstroSat CZTI data with the CIFT framework (Sharma et al,\n2020, arxiv:2011.07067) showed detection of a bright long GRB 210822A,\nwhich was also detected by Swift (Page et al., GCN 30677), GECAM (Wang\net al., GCN 30678), and Fermi-LAT (Ohno et al., GCN 30687). \n\nThe source was clearly detected in the 20-200 keV energy range. The\nlight curve showed multiple peaks of emission with the strongest peak at\n2021-08-22 09:18:17.50 UT. The measured peak count rate associated with\nthe burst is 2190 (+85, -91) cts/s above the background in the combined\ndata of four quadrants, with a total of 12961 (+301, -314) cts. The\nlocal mean background count rate was 530 (+2, -3) cts/s. Using\ncumulative rates, we measure a T90 of 10 (+0.2, -0.2) s.\n\nIt was also clearly detected in the CsI anticoincidence (Veto) detector\nin the 100-500 keV energy range. The light curve showed multiple peaks\nof emission with the strongest peak at 2021-08-22 09:18:18.97 UT. The\nmeasured peak count rate is 3587 (+117, -127) cts/s above the background\nin the combined Veto data of four quadrants, with a total of 24196\n(+541, -655) cts. The local mean background count rate was 1799 (+4, -4)\ncts/s. We measure a T90 of 12 (+0.5, -0.5) s from the cumulative Veto\nlight curve.\n\nCZTI GRB detections are reported regularly on the payload site at\nhttp://astrosat.iucaa.in/czti/?q=grb [1]. CZTI is built by a TIFR-led\nconsortium of institutes across India, including VSSC, ISAC, IUCAA, SAC\nand PRL. The Indian Space Research Organisation funded, managed and\nfacilitated the project. \n\nLinks:\n------\n[1] http://astrosat.iucaa.in/czti/?q=grb",
  "circularId": 30693,
  "createdOn": 1629710027000,
  "email": "gauravwaratkar@iitb.ac.in",
  "subject": "GRB 210822A: AstroSat CZTI detection",
  "submitter": "Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>",
  "eventId": "GRB 210822A"
}