{
  "subject": "IceCube-201222A: Upper limits from a search for additional neutrino events in IceCube",
  "eventId": "IceCube-201222A",
  "bibcode": "2020GCN.29154....1I",
  "createdOn": 1608742478000,
  "circularId": 29154,
  "submitter": "Alex Pizzuto at ICECUBE/U of Wisconsin  <pizzuto@wisc.edu>",
  "email": "pizzuto@wisc.edu",
  "body": "The IceCube Collaboration (http://icecube.wisc.edu/) reports:\n\nIceCube has performed a search for additional track-like muon neutrino events arriving\nfrom the direction of IceCube-201222A (https://gcn.gsfc.nasa.gov/gcn3/29120.gcn3) in a time\nrange of 2 days centered on the alert event time (2020-12-21 00:56:16.14 UTC to 2020-12-23 00:56:16.14 UTC) during which IceCube was collecting good quality data. Excluding the\nevent that prompted the alert, one additional track-like event is found in spatial coincidence\nwith the 90% containment region of IceCube-201222A. We find that these data are consistent with atmospheric background expectations, with a p-value of 1.0. We accordingly derive a time-integrated muon-neutrino flux upper limit at the alert position of E^2 dN/dE = 4.1 x 10^-5 TeV cm^-2 at 90% CL, under the assumption of an E^-2 power law. 90% of events IceCube would detect from a source at this declination with an E^-2 spectrum are approximately between 1 TeV and 1 PeV.\n\nA subsequent search was performed to include the month of data prior to the alert event (2020-11-22 00:56:16.14 UTC to 2020-12-23 00:56:16.14 UTC). In this case, we report a p-value of 1.0, consistent with no significant excess of track-like events, and a corresponding time-integrated muon-neutrino flux upper limit assuming an E^-2 spectrum (E^2 dN/dE) of\n5.5 x 10^-5 TeV cm^-2 at the 90% CL.\n\nThe IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc@icecube.wisc.edu<mailto:roc@icecube.wisc.edu>."
}