{
  "bibcode": "2018GCN.23508....1H",
  "body": "R. Hamburg (UAH) and E. Burns (GSFC) report on behalf of the Fermi-GBM team\nand the GBM+LIGO/Virgo working group:\n\n\n\nFour new binary black hole mergers detections by LIGO/Virgo have been\nreported in GWTC-1, the first catalog of gravitational-wave transients [1].\nWe searched for coincident Fermi-GBM on-board triggers[2], sub-threshold\nshort gamma-ray burst candidates[3], and using the targeted search of\nFermi-GBM data[4]. In no cases did we find significant gamma-ray emission\nin the Fermi-GBM data. We report the GW localization probability observed\nby Fermi-GBM (observing fraction) for each GW at event time:\n\n\nGW  Observing Fraction\nGW170729 88%\nGW170809 78%\nGW170818 100%\nGW170823 0%  (Fermi was transiting the SAA)\n\n\nThe results of the observations around prior gravitational wave signals\nhave been previously published or are reported in GCN circulars.\n\nWe have searched for significant gamma-ray emission in Fermi-GBM around the\nmarginal triggers reported in GWTC-1 and found nothing of immediate\ninterest. The results here are preliminary. The final results and the\npopulation-level analysis are part of on-going work between Fermi-GBM and\nLIGO/Virgo. Upper limits may be presented in this work. The implications of\nthese non-detections on the candidate counterpart around GW150914 are the\nsubject of on-going work.\n\n\n[1] https://arxiv.org/abs/1811.12907\n[2] https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html\n[3] https://gcn.gsfc.nasa.gov/fermi_gbm_subthresh_archive.html\n[4] http://iopscience.iop.org/article/10.1088/0067-0049/217/1/8/meta\n\n\n*The initial circular, GCN 23506, was sent without the author block.\n\n[GCN OPS NOTE(04dec18):  This Circular (23508) superceeds Circular 23506,\nbecause the author resubmitted with a copy that had the authors included.]",
  "circularId": 23508,
  "createdOn": 1543950762000,
  "email": "erickayserburns@gmail.com",
  "subject": "Fermi-GBM Observations During Four New GW-Detected BBH Mergers (Correction)",
  "submitter": "Eric Burns at GSFC  <erickayserburns@gmail.com>"
}