Limitations on the photo-disintegration process as a source of VHE photons

Abstract: We consider whether photo-disintegration is ever able to provide an effective mechanism for the production of VHE γ-ray emission from astrophysical sources. We find that the efficiency of this process is always smaller by a factor A/Z 2 (∼4/A) than that of nuclei cooling through Bethe–Heitler pair-production. Furthermore, for sources optically thin to TeV emission, we find that the efficiency of this process can be no more than 3×10−5(R source/R Larmor), where R source is the source size and R Larmor is the CR nuclei Larmor radius. We conclude that this process is unable to provide an effective mechanism for VHE γ-ray emission from astrophysical sources. [ABSTRACT FROM AUTHOR]