{
  "bibcode": "2017GCN.21924....1M",
  "body": "Israel Martinez (University of Maryland) and\nIgnacio Taboada (Georgia Tech)\nreport on behalf of the HAWC collaboration\n(https://www.hawc-observatory.org/collaboration/):\n\nOn 2017/09/22 20:54:30.43 UTC IceCube detected a track-like,\nvery-high-energy event with a high probability of being of astrophysical\norigin, at RA=77.43d and Dec=5.72d J2000. The up-to-date values were\nreported in GCN circular 21916.\n\nTwo analyses were performed:\n\n* Search for a steady source.\nThis analysis was performed on archival data from November 2014 to\nJune 2017. Assuming a spectral index of -2.5 we searched in a 1.3deg\ncircle around the IceCube reported location.The maximum significance is\n3.5 sigma at RA=76.29deg and Dec=5.04deg. We estimate the number of trials\nto be ~130. We set an upper limit 95% CL on gamma rays for this period of:\n\nE^2 dN/dE = 5.62e-15 (E/7TeV)^-0.5 TeV cm^-2 s^-1.\n\n* Search for a transient source.\nThe event location was not in HAWC's FOV at the time of detection, so\nthis analysis was performed using data corresponding to the two nearest\ntransits (MJD 58018.35-59018.60 and 58019.35-59019.60). Using the same\nspectral index and search window, the maximum significance is 2.4 sigma at\nRA=76.45deg and Dec=5.58deg. We set an upper limit 95% CL on gamma rays\nfor this period of:\n\nE^2 dN/dE = 2.26e-13 (E/7TeV)^-0.5 TeV cm^-2 s^-1.\n\nHAWC is a very-high-energy gamma-ray observatory located in\nCentral Mexico at latitude 19 deg North. It operates day and night with\nover 95% 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": 21924,
  "createdOn": 1506304522000,
  "email": "imc@umd.edu",
  "subject": "IceCube-170922A: HAWC follow-up",
  "submitter": "Israel Martinez at HAWC  <imc@umd.edu>",
  "eventId": "IceCube-170922A"
}