Possible origins of the two γ-ray components C0 and C1 in IC 443

Recent LHAASO observations of IC 443 reveal that its high-energy γ-ray emission can be decomposed into two components with clearly distinct spatial morphologies and spectral properties, namely the compact component C0 and component C1 with an angular extent of 0.67̧irc. We aim to explain the γ-ray emission mechanisms responsible for the two components in IC 443 and to further investigate their respective possible astrophysical counterparts. We modelled components C0 and C1 independently using two different physical scenarios. For component C0, we adopted an supernova remnants interacting with molecular cloud (SNR-MC) hadronic model that accounts for finite source-size effects to describe the escape and diffusion of high-energy particles and their γ-ray production via proton-proton (pp) interactions with the surrounding molecular clouds. For component C1 , we employed a spatially dependent multi-zone leptonic transport model and describe the evolution of high-energy electrons under the combined action of advection, diffusion, and energy losses using a Fokker--Planck-type equation. The model reproduces the SEDs of components C0 and C1 well. Component C0 exhibits a pronounced π^0-decay feature, and the maximum energy of its escaping particles reaches the PeV scale. The γ-ray emission from component C1 can be explained by inverse Compton scattering. Its diffusion coefficient is approximately two orders of magnitude lower than that in the surrounding interstellar medium, and no significant synchrotron counterpart is detected. The γ-ray emission from IC 443 involves the combined action of multiple physical mechanisms. Component C0 may be a potential PeVatron candidate, whereas component C1 may correspond to a potential TeV halo candidate.