The Interaction Between Cosmic Rays Escaping From Suprnova Remnant And Nearby Molecular Clouds

Cosmic rays(CRs) are the high-energy particles coming from the interstel-lar space,including Galactic CRs which mainly refer to particles under1018eV.Generally speaking,supernova remnants(SNRs) are believed to be the sources and the accelerator of Galactic cosmic rays.The particles escaping from nearby SNRs illuminate the dense molecular clouds(MCs) which become targets and amplifiers for γ ray via pp interation.In this paper,we firstly introduce the basic information of CRs and two of strong evidences proving SNRs to be the origin of Galactic CRs.We then fo-cus on the impact on the cosmic rays escaping from nearby SNRs due to the time-dependent source structure and discussing the flux spectrums originating from the burst-like injection、the continuous injection and the δ function injec-tion that the energy dependent CRs escape from SNR respectively. The results show that no matter it is considered from the perspective of geometry or from the diffusion process,the impact on the cosmic rays due to the time-dependent source structure are there and need to be into account.Following,we expound the complex special contact between MCs and SNRs, and compare simply the calculation methods of pp interaction from Kelner, Kamae and Kafexhiu respec-tively. We finally study SNR W28to calculate the γ ray spectrums produced via pp interaction, and compare our results with experimental data,limit the diffusion parameters of the cosmic ray with explanation.