{
  "bibcode": "2016GCN.19870....1P",
  "body": "D. M. Palmer (LANL) reports on behalf of the Swift team:\n\nOn 2016-08-25 at 09:39:29, INTEGRAL SPI ACS reported a \ntrigger (#7539) via GCN.  Examination of the Swift/BAT count rates\nat that time showed a simultaneous detection of a short hard\nburst (duration ~0.1 s, with the detected flux predominantly \nabove 50 keV).\n\nOn-board analysis of the data showed that the highest-significance\npeak in the corresponding image was at a location \nra,dec = 251.982, -7.833 (J2000) with a ~5 arcmin error radius.  \nThis peak is of marginal significance (5.6 sigma) and did not trigger\nan automated follow-up observation.  \n\nA preliminary analysis of the Time-of-Arrival difference between \nINTEGRAL and BAT lightcurves did not exclude this location.\nTherefore, this was considered a possible GRB localization\nand a ToO observation was requested.\n\nSwift-XRT performed follow-up observations of this location, collecting\n2.0 ks of Photon Counting (PC) mode data between T0+55.9 ks and \nT0+62.2 ks.\n\nNo X-ray sources have been detected within the 296 arcsec radius BAT \nerror circle. The 3-sigma upper limit in the field is 0.004 ct s^-1, \ncorresponding to a 0.3-10 keV observed flux of 1.5e-13 erg cm^-2 s^-1 \n(assuming a typical GRB spectrum).\n\nAn uncatalogued source was detected, however this was too far from the GRB\nposition to be the afterglow.\n\nThe results of the XRT-team automatic analysis of the XRT observations,\nincluding a position-specific upper limit calculator, are available at\nhttp://www.swift.ac.uk/ToO_GRBs/00020686.\n\nA more detailed analysis of the light curve TOA difference also\nconclusively excludes the  BAT location as the true burst position.\n(Dmitry Svinkin, private communication).\n\nBased on these observations and analyses, we can exclude the\nmarginal image peak location as being the GRB location.\n\nThe simultaneous INTEGRAL and BAT detections proves that\nthere was a short GRB at that time, but it was most likely outside\nof the BAT's imaging field of view.\n\n[GCN OPS NOTE(26aug16): Per author's request, the mispelling and missing\nword 'source' were fixed.]",
  "circularId": 19870,
  "createdOn": 1472237564000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 160825A: not localized by Swift",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 160825A"
}