{
  "bibcode": "2015GCN.17902....1D",
  "body": "V. D'Elia (ASDC), S. D. Barthelmy (GSFC), P. A. Evans (U. Leicester),  \nL. Izzo (URoma/ICRA) and M. H. Siegel (PSU) report on behalf of the  \nSwift team:\n\n\nWe have analysed 4.5 ks of Swift/XRT data for the Swift/BAT-detected  \npossible burst GRB 150604A (D'Elia et al. GCN Circ. 17901), collected  \nin Photon Counting mode, between 138 s and 21.6 ks after the BAT  \ntrigger. No X-ray sources have been detected inside or close to the  \nSwift/BAT error region. The 3-sigma upper limit at the Swift/BAT  \nposition is ~0.002 ct s^-1, corresponding to a 0.3-10 keV observed  \nflux of ~1e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum).\n\nGround analysis of the BAT data for this trigger shows that the  \nsignificance of the initial detection has dropped below that  \nconsidered to be a valid trigger.\n\nSwift/UVOT began settled observation of the field 142 s after the BAT  \ntrigger. No new source is detected in the initial 1.4 ks of  \nobservation down to a white magnitude limit of 20.9.\n\nTherefore, this trigger is likely due to noise, and not due to  \nanything astrophysical.\n\nThis circular is an official product of the Swift team.",
  "circularId": 17902,
  "createdOn": 1433429881000,
  "email": "delia@asdc.asi.it",
  "subject": "Swift trigger 642453 is not an astrophysical source",
  "submitter": "Valerio D'Elia at ASDC  <delia@asdc.asi.it>"
}