GCN Circular 31706
S. Garrappa (DESY-Zeuthen), S. Buson (Univ. of Wuerzburg) and J. Sinapius (DESY-Zeuthen) on behalf of the Fermi-LAT collaboration: We report an analysis of observations of the vicinity of the high-energy IC220306A neutrino event (GCN 31692) with all-sky survey data from the Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope. The IceCube event was detected on 2022-03-06 03:46:37.06 UTC (T0) with J2000 position RA = 314.82 (+0.54, -0.52) deg, Decl. = 8.61 (+0.47, -0.55) deg 90% PSF containment. No cataloged gamma-ray sources are found within the 90% IC220306A localization error (4FGL-DR3; arXiv:2201.11184; The Fermi-LAT collaboration 2020, ApJS, 247, 33). We searched for the existence of intermediate (months to years) timescale emission from a new gamma-ray transient source. Preliminary analysis indicates no significant (>5sigma) new excess emission (> 100 MeV) within the IC220306A 90% confidence localization. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IC220306A best-fit position, the >100 MeV flux upper limit (95% confidence) is < 1.3e-10 ph cm^-2 s^-1 for ~13-years (2008-08-04 to 2022-03-06 UTC), <4.6e-9 (< 1.3e-7) ph cm^-2 s^-1 for a 1-month (1-day) integration time before T0. Since Fermi normally operates in an all-sky scanning mode, regular monitoring of this source will continue. For this source the Fermi-LAT contact persons are S. Garrappa (simone.garrappa at desy.de) and S. Buson (sara.buson at uni-wuerzburg.de). The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.