{
  "bibcode": "2022GCN.32902....1D",
  "body": "M. Dixit (IITB), R. Gopalakrishnan (IUCAA), G. Waratkar (IITB), V. \nPrasad (IUCAA), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya \n(Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) \nreport on behalf of the AstroSat CZTI collaboration:\n\nAnalysis of AstroSat CZTI data with the CIFT framework (Sharma et al., \n2021, JApA, 42, 73) showed the detection of a long GRB 221027C.\n\nIt was clearly detected in the CsI anticoincidence (Veto) detector in \nthe 100-500 keV energy range. The light curve peaks at 2022-10-27 \n11:01:02.643 UTC. The measured peak count rate is 430.9 (+76.5, -42.7) \ncounts/s above the background in the combined Veto data of all \nquadrants, with a total of 1296 (+366, -418) counts. The local mean \nbackground count rate was 1406.0 (+6.2, -6.7) counts/s. We measure a T90 \nof 5.3 (+5.9, -3.0) s from the cumulative Veto light curve.\n\nThe source was also faintly detected in the 20-200 keV energy range. The \nlight curve peaks at 2022-10-27 11:01:04.500 UTC. The measured peak \ncount rate associated with the burst is 96.1 (+45.0, -6.1) counts/s \nabove the background in the combined data of three quadrants, with a \ntotal of 368 (+128, -149) counts. The local mean background count rate \nwas 349.1 (+2.7, -2.7) counts/s. Using cumulative rates, we measure a \nT90 of 6.4 (+0.6, -3.9) s.\n\nCZTI GRB detections are reported regularly on the payload site at \nhttp://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led \nconsortium of institutes across India, including VSSC, URSC, IUCAA, SAC, \nand PRL. The Indian Space Research Organisation funded, managed, and \nfacilitated the project.",
  "circularId": 32902,
  "createdOn": 1667302791000,
  "email": "gauravwaratkar@iitb.ac.in",
  "subject": "GRB 221027C: AstroSat CZTI detection",
  "submitter": "Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>",
  "eventId": "GRB 221027C"
}