{
  "bibcode": "2019GCN.25174....1B",
  "body": "S. D. Barthelmy (NASA/GSFC), A. Y. Lien (GSFC/UMBC),\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), F. E. Marshall (NASA/GSFC),\nA. 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 S190727h (LIGO/VIRGO Collaboration GCN Circ. 25164),\nwhere T0 is the LVC trigger time (2019-07-27T06:03:33.985 UTC).\n\nThe center of the BAT FOV at T0 is\nRA = 171.271 deg,\nDEC = -3.729 deg,\nand the ROLL angle is 287.727 deg.\nThe BAT Field of View (>10% partial coding) covers 0.05% of the integrated\nLVC localization probability, and 0.04% 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 ~ 6.42 x 10^-8 erg/s/cm^2.\n\nAlso, there is no significant excess in the BAT raw light curves around the\ntime of the possible candidate reported by INTEGRAL at ~T0+4 s\n(Minaev et al. GCN 25171), though the BAT FOV may cover different part\nof the sky than the INTEGRAL FOV around this time.\n\nEvent data are available from T0-14.342 to T0-11.182. No significant\ndetections are found in the 15-350 keV images made using the full\nevent data range.\n\nBAT retains decreased, but significant, sensitivity to rate increases for\ngamma-ray events outside of its FOV. About 59.13% 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/S190727h/web/source.html",
  "circularId": 25174,
  "createdOn": 1564244133000,
  "email": "amy.y.lien@nasa.gov",
  "subject": "LIGO/Virgo S190727h: No counterpart candidates in the Swift/BAT Observations",
  "submitter": "Amy Lien at GSFC  <amy.y.lien@nasa.gov>",
  "eventId": "LIGO/Virgo S190727h"
}