{
  "bibcode": "2020GCN.27617....1A",
  "body": "Hugo Ayala (Penn State) reports on behalf of the HAWC\ncollaboration (http://www.hawc-observatory.org/collaboration):\n\nOn 2020/04/21 00:35:24 UTC, the IceCube collaboration reported a\ntrack-like very-high-energy event  that has a high probability of\nbeing an astrophysical neutrino, IceCube-200421A. Location is at\nRA: 87.93 (+3.49/-2.83 deg  90% PSF containment) J2000\nDec: 8.23 (+2.09/-1.84 deg 90% PSF containment) J2000\n(GCN circular 27612).\n\nWe performed two types of analyses for the follow-up. The first is for\na steady source in archival data and the second is a search for a\ntransient source. We assume a power-law spectrum with an index of -2.3\nfor both analyses.\n\nSearch for a steady source in archival data:\nThe archival data spans from November 2014 to May 2018. We searched\ninside the reported IceCube error region.\nThe highest significance, 2.83 sigma (-0.43 post-trials),\nis at RA 87.19 deg, Dec +7.37 deg (+-0.21 deg 68% containment) J2000.\nWe set a time-integrated 95% CL  upper limit on gamma rays at the\nmaximum position of:\n\nE^2 dN/dE = 2.82e-13 (E/TeV)^-0.3 TeV.cm^-2.s^-1\n\nSearch for a transient source.\n\nSince the IceCube event fall inside the HAWC field of view,\nwe report on the result during the transit of the IceCube\nposition.\n\nData acquisition started on 2020/04/20 19:23:55 UTC and ended\n2020/04/21 01:24:32 UTC.\nThe most significant location, with 3.28 sigma (1.53 post-trials),\nis at RA 85.05 deg, Dec +8.5 (+-0.23 deg 68% containment) deg (J2000).\nWe set a time-integrated 95% CL upper limit at the position of\nmaximum significance of:\n\nE^2 dN/dE = 1.3.e-11 (E/TeV)^-0.3 TeV.cm^-2.s^-1\n\nHAWC is a very-high-energy gamma-ray observatory operating in Central\nMexico at latitude 19 deg. north. Operating day and night with over\n95% duty cycle, HAWC has an instantaneous field of view of 2 sr and\nsurveys 2/3 of the sky every day. It is sensitive to gamma rays from\n300 GeV to 100 TeV.",
  "circularId": 27617,
  "createdOn": 1587503884000,
  "email": "hgayala@psu.edu",
  "subject": "IceCube-200421A: No significant detection in HAWC",
  "submitter": "Hugo Ayala at Pennsylvania State University  <hgayala@psu.edu>",
  "eventId": "IceCube-200421A"
}