Local Stellar Kinematics from RAVE Data-VI. Metallicity Gradients Based on the F-G Main-Sequence Stars

Abstract

We estimated iron and metallicity gradients in the radial and vertical directions with the F and G type dwarfs taken from the Radial Velocity Experiment Data Release 4 database. The sample defined by the constraints Z max ≤ 825 pc and e p≤0.10 consists of stars with metal abundances and space velocity components agreeable with the thin-disc stars. The radial iron and metallicity gradients estimated for the vertical distance intervals 0 < Z max≤500 and 500 < Z max≤1500 pc, are mostly positive. Compatible iron and metallicity gradients could be estimated with guiding radius (R g) for the same vertical distance intervals 0 < Z max≤500 and 500 8 kpc. The range of the iron and metallicity abundance for the F and G type dwarfs on elongated orbits, [-0.13,-0.01), is similar to the thin-disc stars, while at least half of their space velocity components agree better with those of the thick-disc stars. The vertical iron gradients estimated for the F and G type dwarfs on circular orbits are d[Fe/H]/dZmax =-0.176 ± 0.039 dex kpc-1 and d[Fe/H]/dZmax =-0.119 ± 0.036 dex kpc-1 for the intervals Z max≤825 and Z max≤1500 pc, respectively.