{
  "submittedHow": "web",
  "body": "J. Wood (NASA/MSFC) and J. Mangan (CNRS/IJCLab) report on behalf of the Fermi-GBM Team:\n\nFor S230802aq (GCN 34314) and using the initial bayestar skymap, Fermi-GBM was observing 59.4% of the localization probability at event time.\n\nThere was no Fermi-GBM onboard trigger around the event time of the LIGO/Virgo/KAGRA (LVK) detection of GW trigger S230802aq. An automated, blind search for short gamma-ray bursts below the onboard triggering threshold in Fermi-GBM also identified no counterpart candidates. The GBM targeted search, the most sensitive, coherent search for GRB-like signals, was run from +/-30 s around merger time, and also identified no counterpart candidates.\n\nPart of the LVK localization region is behind the Earth for Fermi, located at an RA=335.9, Dec=25.3 with a radius of 67.6 degrees. We therefore set upper limits on impulsive gamma-ray emission for the GW localization region visible to Fermi at merger time. Using the representative soft, normal, and hard GRB-like templates described in arXiv:1612.02395, we set the following 3 sigma flux upper limits over 10-1000 keV, weighted by GW localization probability (in units of 10^-7 erg/s/cm^2):\n\nTimescale  Soft   Normal   Hard \n------------------------------------\n0.128 s:     1.2       2.1       4.6\n1.024 s:     0.3       0.6       1.3\n8.192 s:     0.1       0.1       0.2\n\nAssuming the a posteriori mean luminosity distance of 444 Mpc from the GW detection, we estimate the following intrinsic luminosity upper limits over the 1 keV-10 MeV energy range (in units of 10^48 erg/s):\n\nTimescale  Soft    Normal   Hard \n------------------------------------\n0.128s:       4.3       7.0       25.\n1.024s:       1.0       2.1       7.1\n8.192s:       0.3       0.4       1.3",
  "bibcode": "2023GCN.34319....1W",
  "eventId": "LIGO/Virgo/KAGRA S230802aq",
  "subject": "LIGO/Virgo/KAGRA S230802aq: Upper limits from Fermi-GBM Observations",
  "submitter": "Joshua Wood at NASA/MSFC <joshua.r.wood@nasa.gov>",
  "createdOn": 1691009862888,
  "circularId": 34319
}