511 keV asymmetry at the galactic centre

This computer model of the 511 keV gamma rays coming from the central region of the galaxy matches the asymmetry around the galactic centre. The gamma rays from the galactic centre are symmetrical and the only way to fit the observations was to assume that the asymmetry was caused by gamma rays coming from the inner disc region of the galaxy, not throughout the galaxy. This ties in with the observed distribution of hard low mass X-ray binaries.