{
  "circularId": 34805,
  "eventId": "IceCube-231004A",
  "bibcode": "2023GCN.34805....1A",
  "createdOn": 1696534711169,
  "body": "Hugo Ayala (PSU) reports on behalf of the HAWC\ncollaboration (http://www.hawc-observatory.org/collaboration):\n\nOn 2023/10/04 14:39:41.18 UTC, the IceCube collaboration reported a\ntrack-like very-high-energy event  that has a high probability of\nbeing an astrophysical neutrino, IceCube-231004A. Location is at\nRA: 143.79 (+1.10/-1.01 deg  90% PSF containment) J2000\nDec: 25.04 (+1.03/-1.21 deg 90% PSF containment) J2000\n(GCN circular 34791,34792).\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 October 2021. We searched\ninside the reported IceCube error region.\nThe most significant location, with p-value 2.19e-03 (5.13e-02\npost-trials),\nis at RA 144.67 deg, Dec +24.91 deg (±0.42 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 = 1.11e-13 (E/TeV)^-0.3 TeV.cm^-2.s^-1\n\nSearch for a transient source.\nSince the IceCube event fall inside the HAWC field of view,\nwe report on the result for the transit of the IceCube\nposition.\n\nData acquisition started on 2023/10/04 06:13:44 UTC and ended\n2023/10/04 18:28:44 UTC.\nThe most significant location, with p-value 3.14e-02  (0.53 post-trials),\nis at RA 143.17 deg, Dec +24.79 deg (±0.26 deg 68% containment) J2000.\nWe set a time-integrated 95% CL upper limit at the position of\nmaximum significance of:\n\nE^2 dN/dE = 1.67e-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.\n",
  "subject": "IceCube-231004A: No significant detection in HAWC",
  "submitter": "Hugo Ayala at Pennsylvania State University <hgayala@psu.edu>",
  "submittedHow": "email-legacy"
}