Mechanisms and Distance

The issue of how far away the sources of gamma ray bursts lie is central to proposed mechanisms. If they were local, the required energy in gamma rays is large but not so large. In that case, simpler explanations like "starquakes" in the crusts of neutron stars might be capable of producing them. But if they are at very large distances as the data are now indicating, their intrinsic luminosity must be much too large for a simple explanation like neutron starquakes to be adequate.