Ponente
Descripción
Cygnus is a vast star-forming complex harbouring a population of powerful objects, including massive star clusters and associations, Wolf-Rayet stars, pulsars, and supernova remnants. The multi-wavelength picture is far from understood, in particular the recent LHAASO detection of multi-degree scale diffuse γ-ray emission up to PeV energies. In this talk, I demonstrate that hadronic emission from protons accelerated at a tens-of-kiloyears old, powerful supernova can account for the gamma-ray spectrum at 10 TeV-PeV. Furthermore, the energy dependent morphology is recovered using a 3D molecular cloud model. The supernova maximum energy in the hot, turbulent superbubble environment is estimated from published hydrodynamical simulations of Cygnus OB2 (Vieu et al. 2024). The transport equation is solved to determine the radial distribution of non-thermal particles, which is then used to infer the gamma-ray flux generated in molecular clouds and the neutral medium. To complement the very-high energy model, Fermi-LAT data at GeV-TeV is modelled with inverse-Compton emission of electrons accelerated at the termination shocks of Wolf-Rayet winds in Cygnus OB2. I discuss these results in the context of background from Galactic diffuse emission and other source candidates. I highlight in particular the role of multi-wavelength data to constrain the 3D distribution of molecular clouds.
