{
  "bibcode": "2021GCN.31132....1G",
  "body": "S. Garrappa (DESY-Zeuthen), S. Buson (Univ. of Wuerzburg) and R. de \nMenezes (Univ. of Wuerzburg, Univ. of Sao Paulo) on behalf of the \nFermi-LAT collaboration:\n\nWe report an analysis of observations of the vicinity of the high-energy \nIC211125A neutrino event (GCN 31126) 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 2021-11-25 at 06:22:21.56 \nUT (T0) with J2000 position RA = 43.59 (+ 3.13, - 2.71) deg, Decl. = \n22.59 (+ 1.54, - 2.53) deg (90% PSF containment). Two cataloged \ngamma-ray (>100 MeV) sources are located within the 90% IC211125A \nlocalization region (4FGL-DR2, The Fermi-LAT collaboration 2020, ApJS, \n247, 33). These are 4FGL J0248.0+2232 at 1.46 deg distance, which is \nassociated with the blazar of uncertain type 1RXS J024800.1+223136, and \n4FGL J0258.1+2030 at 2.26 deg distance, which is associated with the BL \nLac object MG3 J025805+2029. Based on a preliminary analysis of the LAT \ndata over the 1-month timescale before T0, these objects are not \nsignificantly detected at gamma-rays.\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 (> 5 sigma) new excess emission (> 100 \nMeV) at the IC211125A best-fit position. Assuming a power-law spectrum \n(photon index = 2.0 fixed) for a point source at the IC211125A best-fit \nposition, the >100 MeV flux upper limit (95% confidence) is < 2.0e-10 ph \ncm^-2 s^-1 for ~13-years (2008-08-04 to 2021-11-25 UTC), and < 1.1e-8�� \nph cm^-2 s^-1 for a 1-month integration time before T0.\n\nDue to the current Fermi-LAT observing profile \n(https://fermi.gsfc.nasa.gov/ssc/observations/types/post_anomaly/) the \nregion of IC211125A is not observable by the LAT since November 12, \n2021. Regular monitoring of this region will be resumed at the beginning \nof December \n(https://fermi.gsfc.nasa.gov/ssc/observations/timeline/posting/). For \nthese observations the Fermi-LAT contact persons are S. Garrappa \n(simone.garrappa at desy.de) and S. Buson (sara.buson at uni-wuerzburg.de).\n\nThe Fermi-LAT is a pair conversion telescope designed to cover the \nenergy band from 20 MeV to greater than 300 GeV. It is the product of an \ninternational collaboration between NASA and DOE in the U.S. and many \nscientific institutions across France, Italy, Japan and Sweden.",
  "circularId": 31132,
  "createdOn": 1637950639000,
  "email": "simone.garrappa@desy.de",
  "subject": "Fermi-LAT Gamma-ray Observations of IceCube-211125A",
  "submitter": "Simone Garrappa at DESY  <simone.garrappa@desy.de>",
  "eventId": "IceCube-211125A"
}