Local Stellar Kinematics from RAVE data - VI. Metallicity Gradients
  Based on the F-G Main-sequence Stars
  We estimated iron and metallicity gradients in the radial and vertical
directions with the F and G type dwarfs taken from the RAVE DR4 database. The
sample defined by the constraints Zmax<=825 pc and ep<=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<Zmax<=500 and 500<Zmax<=800 pc are
d[Fe/H]/dRm=-0.083(0.030) and d[Fe/H]/dRm=-0.048(0.037 )dex/kpc; and
d[M/H]/dRm=-0.063(0.011) and d[M/H]/dRm=-0.028(0.057) dex/kpc, respectively,
where Rm is the mean Galactocentric distance. The iron and metallicity
gradients for less number of stars at further vertical distances,
800<Zmax<=1500 pc, are mostly positive. Compatible iron and metallicity
gradients could be estimated with guiding radius (Rg) for the same vertical
distance intervals 0<Zmax<=500 and 500<Zmax<=800 pc, i.e.
d[Fe/H]/dRg=-0.083(0.030) and d[Fe/H]/dRg=-0.065(0.039) dex/kpc;
d[M/H]/dRg=-0.062(0.018) and d[M/H]/dRg=-0.055(0.045) dex/kpc. 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
sub-sample stars with Rm<=8 kpc, nor for the ones at larger distances, Rm>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 and
d[Fe/H]/dZmax=-0.119(0.036) dex/kpc for the intervals Zmax<= 825 and Zmax<=1500
pc, respectively.
