{
  "bibcode": "2023GCN.34006....1D",
  "circularId": 34006,
  "submitter": "Phil Evans at U of Leicester <pae9@star.le.ac.uk>",
  "subject": "GRB 230616A: Swift-XRT observations",
  "body": "P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), D.N. Burrows (PSU),\nJ. D. Gropp (PSU), S. Dichiara (PSU), A.P. Beardmore (U. Leicester),\nJ.P. Osborne (U. Leicester), E. Ambrosi  (INAF-IASFPA)\tand P.A. Evans\n(U. Leicester) report on behalf of the Swift-XRT team:\n\nSwift-XRT has performed follow-up observations of the IPN-detected\nburst GRB 230616A in a series of observations tiled on the sky. The\ntotal exposure time is 4.6 ks, distributed over 4 tiles; the maximum\nexposure at a single sky location was 2.0 ks. The data were collected\nbetween T0+111.3 ks and T0+140.7 ks, and are entirely in Photon\nCounting (PC) mode. \n\nThree uncatalogued X-ray sources have been detected, however none of\nthem is above the RASS limit or shows definitive signs of fading.\nTherefore, at the present time we cannot identify which, if any, is the\nafterglow. Details of these sources are given below:\n\nSource 1:\n  RA (J2000.0):  192.1005  =  12:48:24.12\n  Dec (J2000.0): +5.4365  =  +05:26:11.4\n  Error: 8.2 arcsec (radius, 90% conf.)\n  Count-rate: 0.0177 [+0.0053, -0.0045] ct s^-1   \n  Distance: 1675 arcsec from IPN position.\n  Flux: (6.8 [+2.1, -1.7])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)\n\nSource 2:\n  RA (J2000.0):  192.2299  =  12:48:55.18\n  Dec (J2000.0): +6.0936  =  +06:05:36.9\n  Error: 5.1 arcsec (radius, 90% conf. [Enhanced position])\n  Count-rate: 0.0125 [+0.0046, -0.0037] ct s^-1   \n  Distance: 820 arcsec from IPN position.\n  Flux: (4.2 [+1.5, -1.3])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)\n\nSource 3:\n  RA (J2000.0):  191.8031  =  12:47:12.74\n  Dec (J2000.0): +5.5136  =  +05:30:48.9\n  Error: 6.0 arcsec (radius, 90% conf.)\n  Count-rate: (5.7 [+3.5, -2.5])e-3 ct s^-1   \n  Distance: 1769 arcsec from IPN position.\n\nThe results of the XRT-team automatic analysis of the tiled XRT\nobservations, including a position-specific upper limit calculator, are\navailable at https://www.swift.ac.uk/xrt_products/TILED_GRB00112.\n\nThis circular is an official product of the Swift-XRT team.\n\n",
  "createdOn": 1687102782037,
  "eventId": "GRB 230616A"
}