{
  "bibcode": "2017GCN.20422....1L",
  "body": "A.Y. Lien (GSFC/UMBC), S.D. Barthelmy (NASA/GSFC), D.M. Palmer (LANL),\nT. Sakamoto (AGU), A. A. Breeveld (MSSL-UCL), A.P. Beardmore (U. Leicester),\nD.N. Burrows (PSU), S. Campana (INAF-OAB), S.B. Cenko (NASA/GSFC),\nG. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA), P. D'Avanzo (INAF-OAB),\nV.D'Elia(ASDC), P.A. Evans (U. Leicester), N. Gehrels (NASA/GSFC),\nP. Giommi (ASI), C. Gronwall (PSU), J. A. Kennea (PSU),\nH.A. Krimm (CRESST/GSFC/USRA), N.P.M. Kuin (UCL-MSSL), D. Malesani (DARK/NBI),\nF.E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), B. Mingo (U. Leicester),\nJ.A. Nousek (PSU), S.R. Oates (Uni. of Warwick), P.T. O'Brien (U. Leicester),\nJ.P. Osborne (U. Leicester), C. Pagani (U. Leicester), K.L. Page (U.Leicester),\nM. Perri (ASDC), J.L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU),\nM.H. Siegel (PSU), G. Tagliaferri (INAF-OAB), E. Troja (NASA/GSFC/UMCP)\nreport on behalf of the Swift team:\n\nWe report the search results in the BAT data within T0 +/- 100 s of the\nLIGO event G268556 (Shawhan et al. GCN Circ. 20364) , where T0 is the\nLIGO trigger time (2017-01-04T10:11:58:599 UTC).\n\nThe BAT pointing position at T0 is\nRA = 166.157 deg,\nDEC = 38.204 deg,\nROLL = 81.247 deg.\nThe BAT Field of View (>0.1 partial coding) covers 48% of the integrated\nLIGO localization probability.\n\nThere are no BAT event data in this time range (usually event data are only\ncollected for ~ 1000 s around the BAT trigger time). Also, no significant\ndetections (signal-to-noise ratio > 4 sigma) are found in the BAT raw light\ncurves with time bins of 64 ms, 1 s, and 1.6 s, respectively. Assuming an\non-axis (100% coded) short GRB with a typical spectrum in the BAT energy range\n(i.e., a simple power-law model with a power-law index of -1.32; Lien & Sakamoto\net al. 2016), the 4-sigma upper limit in the 1-s binned light curve corresponds\nto a flux upper limit (15-350 keV) of ~ 6.0 x 10^-8 erg/s/cm^2.\n\nBAT retains decreased, but significant, sensitivity to rate increases for\ngamma-ray events outside of its FOV. About 19% of the integrated LIGO localization\nprobability was outside of the BAT FOV but above the Earth's limb from Swift's\nlocation, and the corresponding flux upper limits for this region are within roughly\nan order of magnitude of those within the FOV.",
  "circularId": 20422,
  "createdOn": 1484093436000,
  "email": "tsakamoto@phys.aoyama.ac.jp",
  "subject": "LIGO/Virgo G268556: Swift/BAT data search",
  "submitter": "Takanori Sakamoto at Aoyama Gakuin U  <tsakamoto@phys.aoyama.ac.jp>",
  "eventId": "LIGO/Virgo G268556"
}