Local Stellar Kinematics from RAVE Data  VI. Metallicity Gradients Based on the FG MainSequence 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 thindisc stars. The radial iron and metallicity gradients estimated for the vertical distance intervals 0 < Z _{max} ⩽ 500 and 500 < Z _{max} ⩽ 800 pc are d[Fe/H]/dR_m=0.083± 0.030 and d[Fe/H]/dR_m=0.048± 0.037 dex kpc^{1}, and d[M/H]/dR_m=0.063± 0.011 and d[M/H]/dR_m=0.028± 0.057 dex kpc^{1}, respectively, where R _{m} is the mean Galactocentric distance. The iron and metallicity gradients for less number of stars at further vertical distances, 800 < 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 < Z _{max} ⩽ 800 pc, i.e. d[Fe/H]/dR_g=0.083± 0.030 and d[Fe/H]/dR_g=0.065± 0.039 dex kpc^{1}; d[M/H]/dR_g=0.062± 0.018 and d[M/H]/dR_g=0.055± 0.045 dex kpc^{1}. F and G type dwarfs on elongated orbits show a complicated radial iron and metallicity gradient distribution in different vertical distance intervals. Significant radial iron and metallicity gradients could be derived neither for the subsample stars with R _{m} ⩽ 8 kpc, nor for the ones at larger distances, R _{m} > 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 thindisc stars, while at least half of their space velocity components agree better with those of the thickdisc stars. The vertical iron gradients estimated for the F and G type dwarfs on circular orbits are d[Fe/H]/dZ_{max}=0.176± 0.039 dex kpc^{1} and d[Fe/H]/dZ_{max}=0.119± 0.036 dex kpc^{1} for the intervals Z _{max} ⩽ 825 and Z _{max} ⩽ 1500 pc, respectively.
 Publication:

Publications of the Astronomical Society of Australia
 Pub Date:
 November 2015
 DOI:
 10.1017/pasa.2015.44
 arXiv:
 arXiv:1510.01749
 Bibcode:
 2015PASA...32...43P
 Keywords:

 Galaxy: abundances;
 Galaxy: disk;
 Galaxy: evolution;
 stars: abundances;
 Astrophysics  Astrophysics of Galaxies
 EPrint:
 16 pages, including 11 figures and 5 tables, accepted for publication in PASA