{
  "bibcode": "2021GCN.30387....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 long GRB 210704B, which\nwas also detected by Fermi - GBM (Malacaria et al. 2021, GCN 30382). \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\n2021-07-04 16:25:47.5 UT. The measured peak count rate associated with\nthe burst is 296 (+47, -39) cts/s above the background in the combined\ndata of four quadrants, with a total of 3398 (+476, -466) cts. The local\nmean background count rate was 552 (+2, -3) cts/s. Using cumulative\nrates, we measure a T90 of 37 (+8, -7) s. \n\nIt was also clearly detected in the CsI anticoincidence (Veto) detector\nin the 100-500 keV energy range. The Veto light curve showed multiple\npeaks of emission with the strongest peak at 2021-07-04 16:25:46.7 UT.\nThe measured peak count rate is 1642 (+95, -104) cts/s above the\nbackground in the combined Veto data of four quadrants, with a total of\n18239 (+789, -1081) cts. The local mean background count rate was 1864\n(+5, -5) cts/s. We measure a T90 of 34 (+9, -3) s from the cumulative\nVeto light curve. \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, ISAC, IUCAA, SAC,\nand PRL. The Indian Space Research Organisation funded, managed, and\nfacilitated the project.",
  "circularId": 30387,
  "createdOn": 1625544899000,
  "email": "gauravwaratkar@iitb.ac.in",
  "subject": "GRB 210704B: AstroSat CZTI detection",
  "submitter": "Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>",
  "eventId": "GRB 210704B"
}