Predicted 511 keV intensity distributions for the annihilation of all nucleosynthesis positrons, using the estimated mean positron injection rates. From top to bottom, the transport was assumed to be collisionless everywhere (case A, small diffusion coefficient), collisionless in the bulge and ballistic out of it (case B, inhomogeneous case), and ballistic everywhere (case C, large diffusion coefficient). The given intensities correspond to the 511 keV emission from parapositronium and direct annihilation, assuming a positronium fraction of 0.97.