Galactic 1.275‐MeV emission from ONe novae and its detectability by INTEGRAL/SPI

Models of Galactic 1.275-MeV emission produced by the decay of the radionuclide 22Na have been computed. Several frequency–spatial distributions of novae have been investigated using recent results of nova rates and spatial distributions of novae in our Galaxy. These models allow us to estimate the lower limit of the 22Na mass ejected per ONe nova detectable with the future spectrometer (SPI) of the INTEGRAL observatory as a function of the frequency–spatial distribution of ONe novae in the Galaxy. Calculations using recent estimations of the expected 22Na mass ejected per ONe nova show that the detection of the Galactic emission of 1.275-MeV photons will be difficult with the future spectrometer of the INTEGRAL observatory, whereas the cumulative emission around the Galactic Centre has some chance of being detected during the deep survey of the central radian of the Galaxy.