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GCN Circular 28978

Subject
Fermi-LAT Gamma-ray Observations of IceCube-201130A
Date
2020-12-02T08:34:52Z (3 years ago)
From
Simone Garrappa at DESY <simone.garrappa@desy.de>
S. Garrappa (DESY-Zeuthen), S. Buson (Univ. of Wuerzburg) and M. Kadler 
(Univ. of Wuerzburg) on behalf of the Fermi-LAT collaboration:

We report an analysis of observations of the vicinity of the high-energy 
IC201130A neutrino event (GCN 28969) 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 2020-11-30 at 20:21:46.48 
UT (T0) with J2000 position RA = 30.54 (+1.13, -1.31) deg, Decl. = 
-12.10 (+1.15, -1.13) deg (90% PSF containment). One cataloged gamma-ray 
(>100 MeV) source is located within the 90% IC201130A localization 
region. This is the source 4FGL J0206.4-1151 (4FGL, The Fermi-LAT 
collaboration 2020, ApJS, 247, 33), associated with the flat-spectrum 
radio quasar PMN J0206-1150 (Griffith et al. 1994, ApJS, 90, 179) at 
redshift z = 1.663 (Healey et al. 2008, ApJS, 175, 97). Based on a 
preliminary analysis of the LAT data over the timescales of 1-day and 
1-month prior to T0, this object is not significantly detected (> 5 sigma).

We searched for intermediate (days to years) timescale emission from a 
new gamma-ray transient source. Preliminary analysis indicates no 
significant (> 5 sigma) new excess emission (> 100 MeV) at the IC201130A 
best-fit position. Assuming a power-law spectrum (photon index = 2.0 
fixed) for a point source at the IC201130A best-fit position, the >100 
MeV flux upper limit (95% confidence) is < 6.3e-10 ph cm^-2 s^-1 for 
~12-years (2008-08-04 to 2020-11-30 UTC), and < 1.4e-8 (< 1.5e-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 these observations 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.
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