{
  "bibcode": "2017GCN.21061....1B",
  "body": "I. Bartos, S. Countryman (Columbia), C. Finley (U Stockholm), E. \nBlaufuss (U Maryland), R. Corley, Z. Marka, S. Marka (Columbia) on \nbehalf of the IceCube Collaboration\n\nWe searched IceCube online track-like neutrino candidates (GFU) detected \nin a [-500,500] second interval about the LIGO-Virgo trigger G284239.  \nWe compared the candidate source directions of 1 temporally-coincident \nneutrinos to the LIB_SKYMAP skymap, with the following parameters:\n\n#            dt[s]     RA[deg]    Dec[deg]      E[TeV]  Sigma[deg]\n------------------------------------------------------------------\n1.            4.38       136.0        -2.9        0.79    28.2\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 G284239 \nwithin the LIB_SKYMAP skymap.\n\nA coincident neutrino-GW skymap has been posted to GraceDB \n(<https://gracedb.ligo.org/apiweb/events/G284239/files/coinc_skymap_initial_icecube.png,0>). \nA JSON-formatted list of the above neutrinos can be downloaded from \nGraceDB at: \n<https://gracedb.ligo.org/apiweb/events/G284239/files/IceCubeNeutrinoList.json,0>\n\nIn addition, we are performing coincident searches with other IceCube \ndata streams, including the high-energy starting events (HESE) and \nSupernova triggers.  HESE events have typical energies > 60 TeV and \nstart inside the detector volume, leading to a relatively pure event \nsample with a high fraction of astrophysical neutrinos.  The SN trigger \nsystem is sensitive to sudden increases in photomultiplier counts across \nthe detector, which could indicate a burst of MeV neutrinos. We will \nsubmit separate GCN circulars if 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 \nof the IceCube realtime alert system, please refer to \n<http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1610.01814>; for more \ninformation on joint neutrino and gravitational wave searches, please \nrefer to <http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1602.05411>.",
  "circularId": 21061,
  "createdOn": 1493823909000,
  "email": "imrebartos@gmail.com",
  "subject": "LIGO/Virgo G284239: IceCube neutrino observations",
  "submitter": "Imre Bartos at Columbia/LIGO  <imrebartos@gmail.com>",
  "eventId": "LIGO/Virgo G284239"
}