{
  "bibcode": "2019GCN.25533....1L",
  "body": "A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (NASA/GSFC),\nD. M. Palmer (LANL), T. Sakamoto (AGU),\nA. P. Beardmore (U. Leicester), M. G. Bernardini (INAF-OAB),\nA. A. Breeveld (MSSL-UCL), D. N. Burrows (PSU),\nS. Campana (INAF-OAB), S. B. Cenko (NASA/GSFC),\nG. Cusumano (INAF-IASF PA), A. D'Ai (INAF-IASFPA),\nP. D'Avanzo (INAF-OAB), V. D'Elia (ASI-SSDC), S. Emery (UCL-MSSL),\nP. A. Evans (U. Leicester), P. Giommi (ASI), C. Gronwall (PSU),\nD. Hartmann (Clemson U.), J. A. Kennea (PSU), H. A. Krimm (NSF),\nN. P. M. Kuin (UCL-MSSL), D. B. Malesani (DTU Space),\nF. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), J. A. Nousek (PSU),\nS. R. Oates (Uni. of Warwick), P. T. O'Brien (U. Leicester),\nJ. P. Osborne (U. Leicester), C. Pagani (U. Leicester),\nK. L. Page (U.Leicester), M. J. Page (UCL-MSSL), 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 S190828l (LIGO/VIRGO Collaboration GCN Circ. 25503),\nwhere T0 is the LVC trigger time (2019-08-28T06:55:09.887 UTC).\n\nThe center of the BAT FOV at T0 is\nRA = 323.901 deg,\nDEC = 47.455 deg,\nThe roll angle is 351.941 deg.\nThe BAT Field of View (>10% partial coding) covers 21.29% of the integrated\nLVC localization probability, and 21.76% of the galaxy convolved\nprobability (Evans et al. 2016).\n\nWithin T0 +/- 100 s, no significant detections (signal-to-noise ratio\n>~ 5 sigma) are found in the BAT raw light curves with time bins of 64 ms,\n1 s, and 1.6 s. Assuming an on-axis (100% coded) short GRB with a typical\nspectrum in the BAT energy range (i.e., a simple power-law model with a\npower-law index of -1.32, Lien & Sakamoto et al. 2016), the 5-sigma upper\nlimit in the 1-s binned light curve corresponds to a flux upper\nlimit (15-350 keV) of ~ 7.29 x 10^-8 erg/s/cm^2.\n\nNo event data are available within T0 +/- 100 s.\n\nBAT retains decreased, but significant, sensitivity to rate increases for\ngamma-ray events outside of its FOV. About 4.86% of the integrated LVC\nlocalization probability was outside of the BAT FOV but above the\nEarth's limb from Swift's location, and the corresponding flux upper limits\nfor this region are within roughly an order of magnitude higher than those\nwithin the FOV.\n\nThe results of the BAT analysis are available at\nhttps://swift.gsfc.nasa.gov/results/BATbursts/team_web/S190828l/web/source_public.html",
  "circularId": 25533,
  "createdOn": 1567033043000,
  "email": "amy.y.lien@nasa.gov",
  "subject": "LIGO/Virgo S190828l: no counterpart candidates in the Swift/BAT Observations",
  "submitter": "Amy Lien at GSFC  <amy.y.lien@nasa.gov>",
  "eventId": "LIGO/Virgo S190828l"
}