We present iron abundance measurements, based on high resolution spectroscopy, and accurate distance determinations, based on near infrared photometry, for 34 Galactic Cepheids. The new data are used to constrain the Galactic iron abundance gradient in the outer disk, namely from 10 to 14 kpc. We confirm the flattening of the gradient toward the outer disk. In this region we also found an increase in the metallicity dispersion. Current data do not support the occurrence of a jump in the metallicity gradient for Galactocentric distances of the order of 10-12 kpc.
@article{arxiv.0711.3988,
title = {Cepheids as tracers of the metallicity gradient across the Galactic disk},
author = {B. Lemasle and A. Piersimoni and S. Pedicelli and G. Bono and P. Francois and F. Primas and M. Romaniello},
journal= {arXiv preprint arXiv:0711.3988},
year = {2007}
}
Comments
5 pages, 2 figures; to appear in Mem. Soc. Astr. Italiana, Vol. 79/2 (proceeding Cefalu' Workshop "XXI Century Challenges for Stellar Evolution", ed. S. Cassisi & M. Salaris)