W. J. Maciel - Abstract #156ABUNDANCE GRADIENTS IN THE OUTER GALACTIC DISKW. J. Maciel, C. Quireza Galaxy evolution, ed. M. Spite, Astrophys. Space Sci. 265, 269–270 (1999) Radial abundance gradients of the element ratios O/H, Ne/H, S/H, and Ar/H are determined for a sample of disk planetary nebulae, emphasizing the behaviour of th gradients at large galactocentric distances. |