{
  "bibcode": "2022GCN.31412....1S",
  "body": "A. Suresh (IITB), V. Prasad (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.,\n2021, JApA, 42, 73) showed detection of a long GRB 220107B, which was\nalso detected by Fermi-GBM (trigger 663274898/220107793), Fermi-LAT\n(Axelsson et al., GCN 31409) and Swift-XRT (Gropp et al., GCN 31411). \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\n2022-01-07 19:01:45.50 UT. Quadrant B was noisy, and we exclude it from\nfurther analysis. The measured peak count rate associated with the burst\nis 372 (+44 -42) cts/s above the background in the combined data of\nthree quadrants (out of four), with a total of 2558 (+225 -239) cts. The\nlocal mean background count rate was 382 (+2 -2) cts/s. Using cumulative\nrates, we measure a T90 of 19 (+3 -1) 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 2022-01-07 19:01:35.775 UT. The\nmeasured peak count rate is 826 (+81 -85) cts/s above the background in\nthe combined Veto data of four quadrants, with a total of 5424 (+496\n-555) cts. The local mean background count rate was 1721 (+4 -5) cts/s.\nWe measure a T90 of 22 (+2 -3) s from the cumulative Veto light 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": 31412,
  "createdOn": 1641648002000,
  "email": "gauravwaratkar@iitb.ac.in",
  "subject": "GRB 220107B: AstroSat CZTI detection",
  "submitter": "Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>",
  "eventId": "GRB 220107B"
}