{
  "bibcode": "2019GCN.24075....1B",
  "body": "S. D. Barthelmy (NASA/GSFC), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),\nT. Sakamoto (AGU), A. A. Breeveld (MSSL-UCL), A. P. Beardmore (U.\nLeicester),\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), S. Emery (UCL-MSSL), P. A. Evans (U. Leicester),\nP. Giommi (ASI), C. Gronwall (PSU), J. A. Kennea (PSU),\nH. A. Krimm (CRESST/GSFC/USRA), N. P. M. Kuin (UCL-MSSL),\nF. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB),\nB. Mingo (U. Leicester), J. A. Nousek (PSU), S. R. Oates (Uni. of Warwick),\nP. T. O'Brien (U. Leicester), J. P. Osborne (U. Leicester),\nC. Pagani (U. Leicester), K. L. Page (U.Leicester), M. Perri (ASDC),\nJ. L. Racusin (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU),\nM. H. Siegel (PSU), G. Tagliaferri (INAF-OAB), A. Tohuvavohu (PSU),\nE. Troja (NASA/GSFC/UMCP) report on behalf of the Swift team:\n\nWe report the search results in the BAT data within T0 +/- 100 s of the\nLVC event S190408an (LIGO/VIRGO Collaboration GCN Circ. 24069),\nwhere T0 is the LVC trigger time (2019-04-08T18:18:02.288 UTC).\n\nThe center of the BAT FOV at T0 is\nRA = 133.644 deg,\nDEC = 20.099 deg,\nROLL = 291.895 deg.\nThe BAT Field of View (>10% partial coding) covers 0.02% of the integrated\nLVC localization probability.\n\nWithin T0 +/- 100 s, no significant detections (signal-to-noise ratio >~ 5\nsigma)\nare found in the BAT raw light curves with time bins of 64 ms, 1 s, and 1.6\ns,\nrespectively. Assuming an on-axis (100% coded) short GRB with a typical\nspectrum\nin the BAT energy range (i.e., a simple power-law model with a power-law\nindex of -1.32,\nLien & Sakamoto et al. 2016), the 5-sigma upper limit in the 1-s binned\nlight\ncurve corresponds to a flux upper limit (15-350 keV) of ~ 1.49 x 10^-6\nerg/s/cm^2.\n\nBAT retains decreased, but significant, sensitivity to rate increases for\ngamma-ray events outside of its FOV. About 9.37% of the integrated LVC\nlocalization probability was outside of the BAT FOV but above the Earth's\nlimb\nfrom Swift's location, and the corresponding flux upper limits for this\nregion\nare within roughly an order of magnitude of those within the FOV.",
  "circularId": 24075,
  "createdOn": 1554783365000,
  "email": "amy.y.lien@nasa.gov",
  "subject": "LIGO/Virgo S190408an: Swift/BAT data search",
  "submitter": "Amy Lien at GSFC  <amy.y.lien@nasa.gov>",
  "eventId": "LIGO/Virgo S190408an"
}