On the Galactic disc age–metallicity relation

Abstract

A comparison is made between the age-metallicity relations obtained from four different types of studies: F and G stars in the solar neighbourhood, analysis of open clusters, galactic structure studies with the stellar population synthesis technique and chemical evolution models. Metallicities of open clusters are corrected for the effects of the radial gradient, which we find to be 20.09 dex kpc 21 and most likely constant in time. We do not correct for the vertical gradient, because its existence and value are not firmly established.