{
  "bibcode": "2020GCN.27879....1B",
  "body": "S. Buson (Univ. of Wuerzburg) and S. Garrappa (DESY-Zeuthen) on behalf \nof the Fermi-LAT collaboration:\n\nWe report an analysis of observations of the vicinity of the high-energy \nIC200530A neutrino event (GCN 27865) 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 2020-05-30 07:54:29.43 UT \n(T0) with J2000 position RA =�255.37 (+2.48, -2.56) deg, Decl. = 26.61 \n(+2.33, -3.28) deg 90% PSF containment. Two cataloged >100 MeV gamma-ray \nsources are located within the 90% IC200530A localization error. These \nare 4FGL J1702.2+2642 (associated with the BL Lac object�MG2 \nJ170210+2643) and 4FGL J1659.0+2627 (associated with the FSRQ�4C \n+26.51). Based on a preliminary analysis of LAT data at timescales of \n1-month and 1-day prior to T0, these objects are not significantly \ndetected (>5sigma).\n\nWe searched for the existence of intermediate (days to years) timescale \nemission from a new gamma-ray transient source.�Preliminary analysis \nindicates no significant (>5sigma) new excess emission (>100 MeV) at \nthe�IC200530A best-fit position.�Assuming a power-law spectrum (photon \nindex = 2.0 fixed) for a point source at the IceCube best-fit position, \nthe >100 MeV flux upper limit (95% confidence) is < 2.4e-10 ph cm^-2 \ns^-1 for ~11-years (2008-08-04 / 2020-05-30 UTC), < 1e-8 (< 1.7e-7) ph \ncm^-2 s^-1 for a 1-month (1-day) integration time before T0.\n\nIn the analysis of the ~11-years integrated LAT data (0.1 - 800 GeV), a \n4.0 sigma new excess of gamma rays, Fermi J1707.0+2528�,�was detected \n1.7 deg offset from the best-fit IC200530A position and within the 90% \nconfidence localization of the direction of the neutrino. Assuming a \npower-law spectrum, the best-fit localization is (J2000) RA: 256.77, \nDec:�25.48 (12 arcmin 95% containment, 7 arcmin 68% containment). The \ngamma-ray best-fit spectral parameters are flux = (1.2+/-0.4)e-9 ph \ncm^-2 s^-1 and index = 2.2+/-0.2. In a preliminary analysis of the LAT \ndata over 1-day and 1-month prior T0, Fermi J1707.0+2528�is not \nsignificantly detected in the LAT data.\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. Buson (sara.buson at uni-wuerzburg.de \n<http://uni-wuerzburg.de/>) and�S. Garrappa (simone.garrappa at desy.de \n<http://desy.de/>). The Fermi LAT is a pair conversion telescope \ndesigned to cover the energy band from 20 MeV to greater than 300 GeV. \nIt is the product of an international collaboration between NASA and DOE \nin the U.S. and many scientific institutions across France, Italy, Japan \nand Sweden.",
  "circularId": 27879,
  "createdOn": 1591014131000,
  "email": "simone.garrappa@desy.de",
  "subject": "Fermi-LAT Gamma-ray Observations of IceCube-200530A",
  "submitter": "Simone Garrappa at DESY  <simone.garrappa@desy.de>",
  "eventId": "IceCube-200530A"
}