{
  "bibcode": "2006GCN..4835....1P",
  "body": "M. Perri, M. Capalbi, L. Vetere (ASDC) L.A. Antonelli (ASDC/INAF-OAR),\nG. Tagliaferri (INAF-0AB), D.N. Burrows (PSU) and J.R. Cummings\n(GSFC/ORAU) report on behalf of the Swift XRT team:\n\nThe Swift XRT began observing the field of GRB 060223B (trigger #192152,\nCummings et al., GCN 4821) at 2006-02-24 14:46:47 UT, approximately 19\nhours after the BAT trigger. In a first XRT exposure of ~10 ks we find a\nmarginal detection (5 net photons, SNR=2) of a faint uncatalogued X-ray\nsource at the following coordinates:\n\nRA(J2000) = 16h 56m 58.8s\nDec(J2000) = -30d 48' 46\" is\n\nwith an estimated uncertainty  of 10 arcseconds (90% containment).\nThis position lies 30 arcseconds from the BAT refined position reported\nby Fenimore et al. (GCN 4825).\n\nThe PSF corrected count rate is (7.5 +/- 3.9)e-4 cts/s, corresponding to\nan unabsorbed 0.3-10 keV flux of about 5e-14 erg/cm2/s assuming a\npower law spectrum with a photon index of 2 and Galactic absorption\nof 1.8e21 cm^-2.\n\nIn a second exposure of  about 9 ks, starting ~29 hours after the\ntrigger, the source is not detected.\n\nWe note that due to the small number of counts this source could be\na statistical fluctuation of the background and should be regarded as\na possible X-ray afterglow candidate.\n\nThis circular is an official product of the Swift XRT Team.",
  "circularId": 4835,
  "createdOn": 1140902545000,
  "email": "perri@asdc.asi.it",
  "subject": "GRB 060223B: Swift XRT possible afterglow",
  "submitter": "Matteo Perri at ISAC/ASDC  <perri@asdc.asi.it>",
  "eventId": "GRB 060223B"
}