Can the integral-spectrometer SPI detect supernova signatures in the cosmic-diffuse gamma-ray background?

Although recently a big step forward in the accurate measurement of the spectrum of the cosmic-diffuse low-energy (100 keV - 10 MeV) gamma-ray background (CDB) has been made, its origin is still not yet well understood. Cosmological supernovae, among other source classes, are being discussed as possible contributors in this energy range. In these violent explosions radioactive nuclei are produced which decay emitting copious gamma-rays. These gamma-rays could provide a significant fraction of the CDB around 1 MeV. The calculated spectrum of the integrated emission shows characteristic steps or edges at clearly-defined energies. These features result from the integrated line emission at different redshifts. Here it is investigated if these structures can be detected with the INTEGRA L-spectro meter SPI. First results of this work will be presented.