[vsnet-grb-info 22966] Fermi-LAT Gamma-ray Observations of IceCube-190712A

GCN Circulars gcncirc at capella2.gsfc.nasa.gov
Sat Jul 13 20:28:18 JST 2019


TITLE:   GCN CIRCULAR
NUMBER:  25065
SUBJECT: Fermi-LAT Gamma-ray Observations of IceCube-190712A
DATE:    19/07/13 11:27:05 GMT
FROM:    Simone Garrappa at DESY  <simone.garrappa at desy.de>

S. Garrappa (DESY-Zeuthen, DE), R. Angioni (MPIfR-Bonn, Germany) and S. 
Buson (Univ. of Wuerzburg, DE; UMBC, USA) on behalf of the Fermi-LAT 
collaboration:

We report an analysis of observations of the vicinity of the high-energy 
IC190712A neutrino event (GCN 25057) 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 2019-07-12 01:15:17 UTC 
(T0) with J2000 position RA = 76.46 (+5.09 -6.83) deg, Decl. = 13.06 
(+4.48 -3.44) deg 90% PSF containment.

We searched for the existence of intermediate (months to years) 
timescale emission from a new gamma-ray transient source at the best-fit 
IC190712A position. Preliminary analysis indicates no significant 
(>5sigma) excess emission (>100 MeV) at the best-fit IC190712A position. 
Assuming a power-law spectrum (photon index = 2.0 fixed) for a point 
source at the IceCube best-fit position, the >100 MeV flux upper limit 
(95% confidence) is < 2.3e-10 ph cm^-2 s^-1 for ~10.9-years (2008-08-04 
/ 2019-07-05 UTC) and < 6e-9 (1e-7)  ph cm^-2 s^-1 for a 1-month (1-day) 
integration time before T0.

Several cataloged gamma-ray sources are found within the 90% PSF 
containment of IC190712A position. None of these is significantly 
detected in the 1-month and 1-day scale 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 
<http://desy.de/>) and R. Angioni (angioni atmpifr-bonn.mpg.de 
<http://mpifr-bonn.mpg.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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