W. J. Maciel -
Abstract #125
METALLICITY GRADIENTS IN THE MILKY WAY
W. J. Maciel, R. D. D. Costa,
IAU Symp. 265, Chemical abundances in the Universe: Connecting the first
Stars to Planets, Ed. K. Cunha, M. Spite, B. Barbuy,
CUP, vol. 5, 317-324 (2010)
Radial metallicity gradients are observed in the disks of the Milky Way and in several other
spiral galaxies. In the case of the Milky Way, many objects can be used to determine the
gradients, such as HII regions, B stars, Cepheids, open clusters and planetary nebulae. Several
elements can be studied, such as oxygen, sulphur, neon, and argon in photoionized nebulae, and
iron and other elements in cepheids, open clusters and stars. As a consequence, the number
of observational characteristics inferred from the study of abundance gradients is very large,
so that in the past few years they have become one of the main observational constraints of
chemical evolution models. In this paper, we present some recent observational evidences of
abundance gradients based on several classes of objects. We will focus on (i) the magnitude of
the gradients, (ii) the space variations, and (iii) the evidences of a time variation of the
abundance gradients. Some comments on recent theoretical models are also given, in an effort
to highlight their predictions concerning abundance gradients and their variations.
