The radial metallicity gradient in the Galactic disk

Abstract

The aim of this work is to estimate the radial metallicity gradient in the Galactic disk toward the anticenter direction. For that we use Str¨omgren photometric data which allow us to compute individual physical parameters through empirical calibrations. We detect that metallicity calibrations found in the literature present discontinuities between photometric regions. By this, in the present work we focused in region 4, that is F0-G2 stars. Even thought we detect some critical classification errors when faint stars are treated, induced by its larger observational uncertainties. To account for that, here we propose to use additionally the infra-red 2MASS photometry to clean the sample. We confirm that the metallicity gradient exists and decreases as we move away from the Galactic center...