The 511 keV sky as seen by INTEGRAL/SPI, CGRO/OSSE, SMM/GRS and WIND/TGRS combined

Over more than 30 years three space-borne spectrometers have accumulated a wealth of data on the angular and spectral distribution of the 511 keV Galactic e⁺/e^- annihilation radiation: GRS on the Solar Maximum Mission monitored the 511 keV line from the Galactic Center region in the eighties, the first maps of the inner Galaxy were produced by OSSE/CGRO in the nineties, and since 2002 SPI/INTEGRAL has been performing high resolution imaging spectroscopy over the entire sky. Until now our understanding of the 511 keV emission, and hence of the origin of the Galactic positrons, has been largely based on the analysis of the data-sets independently. We present an analysis of the combined data, constraining the spatial distributions of the galactic e⁺/e^- annihilation radiation by fitting the same models to the SPI data and to those from other instruments.