FSRQ 3C 395: Upper limits from a neutrino search with IceCube
ATel #18041; Shi Yan (University of Wisconsin-Madison), Anna Franckowiak (Ruhr-University Bochum) for the IceCube Collaboration
on 14 Sep 2026; 14:20 UT
Credential Certification: Anna Franckowiak (anna.franckowiak@desy.de)
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
IceCube has performed a search for track-like muon neutrino events arriving from the direction of FSRQ 3C 395 following a report from Fermi LAT(ATel #18013). We analyzed a time window of 42 days to cover the reported enhanced emission phases in gamma rays (2026-07-15 12:00:00.00 UTC to 2026-08-26 12:00:00.00 UTC), during which IceCube was collecting good quality data.
For this search, we report a p-value of 1.0 with respect to an atmospheric background-only hypothesis. We accordingly derive a time-integrated muon-neutrino flux upper limit
for this source of E^2 dN/dE = 6.5e-2 GeV cm^-2 at 90% confidence level, for an E^-2 power law. 90% of events IceCube would detect from a source at this declination with an E^-2 spectrum are between 700 GeV and 500 TeV.
The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime
alert point of contact can be reached at roc@icecube.wisc.edu.
[1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021)
