{
  "bibcode": "2023GCN.34328....1N",
  "circularId": 34328,
  "subject": "GRB 230803A: AstroSat CZTI detection",
  "submitter": "Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>",
  "eventId": "GRB 230803A",
  "submittedHow": "web",
  "body": "P. K. Navaneeth (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:\n\nAnalysis of AstroSat CZTI data with the ML pipeline (Abraham et al., 2021, MNRAS, 504, 3084) and the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a bright long GRB 230803A which was also detected by Fermi (Fermi GBM Team, GCN Circ. 34325).\n\nThe source was clearly detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2023-08-03 01:28:42.50 UTC. The measured peak count rate associated with the burst is 783 (+56, -59) counts/s above the background in the combined data of all quadrants, with a total of 5492 (+498, -481) counts. The local mean background count rate was 430 (+3, -3) counts/s. Using cumulative rates, we measure a T90 of 25 (+2, -1) s. In the preliminary analysis, we find 371 Compton events associated with this event.\n\nThe source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2023-08-03 01:28:42.63 UTC. The measured peak count rate associated with the burst is 2196 (+97, -102) counts/s above the background in the combined data of all quadrants, with a total of 15329 (+934, -934) counts. The local mean background count rate was 1365 (+7, -5) counts/s. We measure a T90 of 26 (+2, -1) s from the cumulative Veto light curve.\n\nCZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.\n\nCZTI GRB detections are reported regularly on the payload site at: \nhttp://astrosat.iucaa.in/czti/?q=grb",
  "createdOn": 1691064298973
}