{
  "bibcode": "2022GCN.31863....1G",
  "body": "R. Gopalakrishnan (IUCAA), V. Prasad (IUCAA), G. Waratkar (IITB), A.\nVibhute (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 220408B which was\nalso detected by Fermi-GBM (GCN 31854).\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\n2022-04-08 07:28:08.50 UT. The measured peak count rate associated with\nthe burst is 1181 (+79, -36) counts/s above the background in the\ncombined data of all four quadrants, with a total of 12408 (+531, -419)\ncounts. The local mean background count rate was 516 (+2, -4) counts/s.\nUsing cumulative rates, we measure a T90 of  25 (+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 2022-04-08 07:28:08.19 UT. The\nmeasured peak count rate is 1215 (+93, -70) counts/s  above the\nbackground in the combined Veto data of four quadrants, with a total of\n10873 (+743, -663) counts. The local mean background count rate was 1882\n(+4, -5) counts/s. We measure a T90 of 24 (+2, -6) 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 [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 \n\nLinks:\n------\n[1] http://astrosat.iucaa.in/czti/?q=grb",
  "circularId": 31863,
  "createdOn": 1649504291000,
  "email": "gauravwaratkar@iitb.ac.in",
  "subject": "GRB 220408B: AstroSat CZTI detection",
  "submitter": "Gaurav Waratkar at IIT,Bombay  <gauravwaratkar@iitb.ac.in>",
  "eventId": "GRB 220408B"
}