{
  "bibcode": "2021GCN.31258....1G",
  "body": "S. Garrappa (DESY-Zeuthen), S. Buson (Univ. of Wuerzburg) and J. \nSinapius (DESY-Zeuthen) on behalf of the Fermi-LAT collaboration:\n\nWe report an analysis of observations of the vicinity of the high-energy \nIC211216B neutrino event (GCN 31249) with all-sky survey data from the \nLarge Area Telescope (LAT), on board the Fermi Gamma-ray Space \nTelescope. The IceCube event was detected on 2021-12-16 23:41:13.93 UTC \n(T0) with J2000 position RA = 199.34 (+1.66, -1.78) deg, Decl. = 17.04 \n(+1.39, -1.36) deg 90% PSF containment. Two cataloged >100 MeV gamma-ray \nsources are located within the 90% IC211216B localization error. No \ncataloged gamma-ray sources are found within the 90% IC211216B \nlocalization error (The Fourth Fermi-LAT catalog DR2; The Fermi-LAT \ncollaboration 2020, ApJS, 247, 33).\n\nWe searched for the existence of intermediate (months to years) \ntimescale emission from a new gamma-ray transient source. Preliminary \nanalysis indicates no significant (>5sigma) new excess emission (0.1 - \n300 GeV) within the IC211216B 90% confidence localization. Assuming a \npower-law spectrum (photon index = 2.0 fixed) for a point source at the \nIceCube best-fit position, the >100 MeV flux upper limit (95% \nconfidence) is < 3.6-10 ph cm^-2 s^-1 for ~13-years (2008-08-04 / \n2021-12-16 UTC), < 1.8e-8 (< 1.2e-7) ph cm^-2 s^-1 for a 1-month (1-day) \nintegration time before T0.\n\nSince Fermi normally operates in an all-sky scanning mode, regular \nmonitoring of this source will continue. For these observations the \nFermi-LAT contact persons are S. Garrappa (simone.garrappa at desy.de) \nand S. Buson (sara.buson at uni-wuerzburg.de). The Fermi LAT is a pair \nconversion telescope designed to cover the energy band from 20 MeV to \ngreater than 300 GeV. It is the product of an international \ncollaboration between NASA and DOE in the U.S. and many scientific \ninstitutions across France, Italy, Japan and Sweden.",
  "circularId": 31258,
  "createdOn": 1639789800000,
  "email": "simone.garrappa@desy.de",
  "subject": "Fermi-LAT Gamma-ray Observations of IceCube-211216B",
  "submitter": "Simone Garrappa at DESY  <simone.garrappa@desy.de>",
  "eventId": "IceCube-211216B"
}