Restrictions on the injection energy of positrons annihilating near the galactic center

One of the interesting and still unsolved problems is the origin of 511 keV annihilation emission from the Galactic Bulge. One of the criterion, which may discriminate between different mechanisms of positron production there, is the positron energy injection. Beacom and Yüksel (2006) suggested a method to estimate this energy from the ratio of the 511 keV line to the MeV in-flight annihilation fluxes. From the COMPTEL data they derived that the maximum injection energy of positron should be about several MeV that cuts down significantly a class of models of positron origin in the GC. However, observations show that the strength of magnetic field in the GC is much higher than in other parts of the Galaxy. We show that if positrons injection in the GC is non-stationary and the magnetic field strength is higher than 0.5 mG both radio and gamma-ray restrictions permit their energy to be higher than hundreds of MeV.