High energy protons produced by various sources of cosmic rays, e.g., supernova remnants, pulsar wind nebulae, active galactic nuclei and gamma-ray bursts, participate in pγ and pp interactions. Although pp interacti...High energy protons produced by various sources of cosmic rays, e.g., supernova remnants, pulsar wind nebulae, active galactic nuclei and gamma-ray bursts, participate in pγ and pp interactions. Although pp interactions may be the dominant mechanism in our Galaxy, it is unclear how important Pγ process is. We show that the upper bound on the fraction of total number of protons participating in pγ interactions inside all Galactic astrophysical sources of cosmic rays is 10%.展开更多
基金This work was supported by NASA under grants NNG05GB67G and NNG06GH62G and the National Natural Science Foundation of China （grant No. 10640420144）.
文摘High energy protons produced by various sources of cosmic rays, e.g., supernova remnants, pulsar wind nebulae, active galactic nuclei and gamma-ray bursts, participate in pγ and pp interactions. Although pp interactions may be the dominant mechanism in our Galaxy, it is unclear how important Pγ process is. We show that the upper bound on the fraction of total number of protons participating in pγ interactions inside all Galactic astrophysical sources of cosmic rays is 10%.
