{
  "bibcode": "2019GCN.25196....1H",
  "body": "R. Hamburg (UAH) reports on behalf of the Fermi-GBM Team and the\nGBM-LIGO/Virgo group:\n\nFor the LIGO/Virgo detection of GW trigger S190728q (GCN 25187) and using\nthe triple-detector BAYESTAR skymap, Fermi-GBM was observing 84.1% of the\nlocalization probability at event time.\n\nApproximately 15 min before the S190728q event, GBM triggered onboard\nto the short gamma-ray burst GRB 190728A (GCN 25181). However based\non the large temporal offset and the difference in localization, this\ntrigger is\nnot considered a likely counterpart.\n\nAn automated, blind search for short gamma-ray bursts below the onboard\ntriggering threshold in Fermi-GBM also identified no counterpart\ncandidates. The GBM targeted search, the most sensitive, coherent search\nfor GRB-like signals, was run from +/- 30 s around merger time, and also\nidentified no counterpart candidates.\n\nPart of the LVC localization region is behind the Earth for Fermi,\nlocated at RA = 129.9 and Dec = -11.1 with a radius of 67.5 degrees.\nWe therefore set upper limits on impulsive gamma-ray emission for\nthe LVC localization region visible to Fermi at merger time. Using\nthe representative soft, normal, and hard GRB-like templates described\nin arXiv:1612.02395, we set the following 3 sigma flux upper limits\nover 10-1000 keV, weighted by GW localization probability, (in units\nof 10^-7 erg/s/cm^2):\n\nTimescale  soft   norm   hard\n--------------------------------------\n0.128 s:    5.3   6.0   15.0\n1.024 s:    2.0   2.7    4.2\n8.192 s:    0.6   0.8    1.1\n\nAssuming the median luminosity distance of 795 Mpc (z=0.165) from the GW\ndetection, we estimate the following intrinsic luminosity upper limits over\nthe 1 keV-10 MeV energy range (in units of 10^49 erg/s):\n\nTimescale  soft   norm   hard\n--------------------------------------\n0.128 s:   6.2    6.4    27.0\n1.024 s:   2.3    2.9    7.6\n8.192 s:   0.7    8.6    2.0",
  "circularId": 25196,
  "createdOn": 1564319340000,
  "email": "rkh0007@uah.edu",
  "subject": "LIGO/Virgo S190728q: Upper limits from Fermi-GBM Observations",
  "submitter": "Rachel Hamburg at UAH  <rkh0007@uah.edu>",
  "eventId": "LIGO/Virgo S190728q"
}