We discuss the discovery potential of extended very-high-energy ( VHE ) neutrino sources by the future KM3 Neutrino Telescope ( KM3NeT ) in the context of the constraining power of the Cherenkov Telescope Array ( CTA ) , designed for deep surveys of the sky in VHE gamma rays .
The study is based on a comparative analysis of sensitivities of KM3NeT and CTA .
We show that a minimum gamma-ray energy flux of E ^ { 2 } \phi _ { \gamma } ( 10 ~ { } \textrm { TeV } ) > 1 \times 10 ^ { -12 } TeV cm ^ { -2 } s ^ { -1 } is required to identify a possible neutrino counterpart with a 3 \sigma significance and 10 years of KM3NeT observations with upgoing muons , if the source has an angular size of R _ { src } = 0.1 deg and emits gamma rays with an E ^ { -2 } energy spectrum through a full hadronic mechanism .
This minimum gamma-ray flux is increased to the level of E ^ { 2 } \phi _ { \gamma } ( 10 ~ { } \textrm { TeV } ) > 2 \times 10 ^ { -11 } TeV cm ^ { -2 } s ^ { -1 } in case of sources with radial extension of R _ { src } = 2.0 deg .
The analysis methods are applied to the supernova remnant RX J1713.7-3946 and the Galactic Center Ridge , as well as to the recent HAWC catalog of multi-TeV gamma-ray sources .