| Photoerosion is a process by which a high energy photon interacts with a nucleus, knocking out a particle such as a proton or neutron, and leaving a smaller nucleus. This process could be capable of changing the abundances of light elements in environments with a large flux of energetic photons.;One such environment is an active galactic nucleus (AGN). In this case, the abundances of isotopes of lithium, beryllium and boron are of particular interest, as they can be produced from an abundant progenitor, carbon, and their production is interesting to studies of big bang nucleosynthesis. It was found that the production of these elements by photoerosion is potentially so large that it is possible to place limits on any AGN phase that the Milky Way may have undergone.;Another type of astrophysical environment with a high photon flux is the neighborhood of a gamma-ray burster. Many theories exist as to the mechanism which causes bursts, but none is widely accepted. Therefore, any diagnostic which could provide information about a burst environment is of interest. If there are any nuclei in the region near a burster, photoerosion might provide such a diagnostic. In this case, the photoerosion products of interest are unstable nuclides, whose decay might be detected at earth. It was found that such signals are below detection limits of current instruments. However, another signal, the decay of positrons also produced by photonuclear reactions, is predicted to be observable for many parameters of the burst region. Furthermore, the strength and time behavior of both types of signals would contain valuable information about the neighborhood near a burst, and any redshift of these signals would provide a direct measurement of the distance scale to gamma-ray. |
