{
  "bibcode": "2017GCN.21432....1B",
  "body": "I. Bartos, S. Countryman (Columbia), C. Finley (U Stockholm), E. Blaufuss\n(U Maryland), R. Corley, Z. Marka, S. Marka (Columbia) on behalf of the\nIceCube Collaboration\n\nWe searched IceCube online track-like neutrino candidates (GFU) detected in\na [-500,500] second interval about the LIGO-Virgo trigger G296853. We\ncompared the candidate source directions of 4 temporally-coincident\nneutrinos to the BAYESTAR skymap, with the following parameters:\n\n#            dt[s]     RA[deg]    Dec[deg]      E[TeV]  Sigma[deg]\n------------------------------------------------------------------\n1.         -310.02        65.9        -5.2        1.11         0.5\n2.         -128.45        74.0       -29.2       52.68         0.2\n3.          361.60       164.0       -14.6       20.50         0.5\n4.          438.49       121.1       -64.8       81.83         2.1\n\n\n(dt--time from GW in [seconds]; RA/Dec--sky location in [degrees];\nE--reconstructed secondary muon energy in [TeV]; Sigma--uncertainty of\ndirection reconstruction in [degrees])\n\nThe analysis found NO COINCIDENT ONLINE TRACK-LIKE NEUTRINO CANDIDATES\ndetected by IceCube within the 500 second window surrounding G296853 within\nthe BAYESTAR skymap.\n\nA coincident neutrino-GW skymap has been posted to GraceDB (<\nhttps://gracedb.ligo.org/apiweb/events/G296853/files/\ncoinc_skymap_initial_icecube.png,0>). A JSON-formatted list of the above\nneutrinos can be downloaded from GraceDB at: <https://gracedb.ligo.org/\napiweb/events/G296853/files/IceCubeNeutrinoList.json,0>\n\nIn addition, we are performing coincident searches with other IceCube data\nstreams, including the high-energy starting events (HESE) and Supernova\ntriggers.  HESE events have typical energies > 60 TeV and start inside the\ndetector volume, leading to a relatively pure event sample with a high\nfraction of astrophysical neutrinos.  The SN trigger system is sensitive to\nsudden increases in photomultiplier counts across the detector, which could\nindicate a burst of MeV neutrinos.  We will submit separate GCN circulars\nif coincident HESE or SN triggers are found.\n\nThe IceCube Neutrino Observatory is a cubic-kilometer neutrino detector\noperating at the geographic South Pole, Antarctica.  For a description of\nthe IceCube realtime alert system, please refer to <\nhttp://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1610.01814>; for more\ninformation on joint neutrino and gravitational wave searches, please refer\nto <http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1602.05411>.",
  "circularId": 21432,
  "createdOn": 1502274993000,
  "email": "stefan.countryman@ligo.org",
  "subject": "LIGO/Virgo G296853: IceCube neutrino observations",
  "submitter": "Stefan Countryman at LIGO Scientific Collaboration  <stefan.countryman@ligo.org>",
  "eventId": "LIGO/Virgo G296853"
}