Modelling hard gamma-ray emission from supernova remnants

The observation by the CANGAROO experiment of TeV emission from SN 1006, inconjunction with several instances of non-thermal X-ray emission from supernovaremnants, has led to inferences of super-TeV electrons in these extendedsources. While this is sufficient to propel the theoretical community in theirmodelling of particle acceleration and associated radiation, the anticipatedemergence in the next decade of a number of new experiments probing the TeV andsub-TeV bands provides further substantial motivation for modellers. Inparticular, the quest for obtaining unambiguous gamma-ray signatures of cosmicray ion acceleration defines a ``Holy Grail'' for observers and theoristsalike. This review summarizes theoretical developments in the prediction ofMeV-TeV gamma-rays from supernova remnants over the last five years, focusingon how global properties of models can impact, and be impacted by, hardgamma-ray observational programs, thereby probing the supernova remnantenvironment. Properties of central consideration include the maximum energy ofaccelerated particles, the density of the unshocked interstellar medium, theambient magnetic field, and the relativistic electron-to-proton ratio. Criteriafor determining good candidate remnants for observability in the TeV band areidentified.Comment: 10 pages, 2 figures, to appear in Proc. of Snowbird TeV Gamma-Ray Workshop ed. B. L. Dingus (AIP, New York, 2000) (Replacement updates Fig. 2 and references