Constraining the PeV gamma-ray emission zone of Cygnus X-3 with contemporaneous GeV timing and spectral observations

Xing-Fu Zhang, Ruo-Yu Liu, Dmitriy Khangulyan +2

Cygnus X-3 has recently been established as a variable ultra-high-energy(UHE) gamma-ray source with photons detected up to 3.7~PeV. The temporal correlation between its PeV activit…