Deep SDSS Optical Spectroscopy. II.

This work follows the same methodology as in the previous paper in this series, deriving atmospheric parameters by chi^2^ minimization, but we now obtain the abundances of individual elements by fitting their associated spectral lines.

Distances are calculated from absolute magnitudes obtained by a statistical comparison of our stellar parameters with stellar-evolution models. The observations reveal a decrease in the abundances of iron, calcium and magnesium at large distances from the Galactic center. The median abundances for the halo stars analyzed are fairly constant up to a Galactocentric distance r~20kpc, rapidly decrease between r~20 and r~40kpc, and flatten out to significantly lower values at larger distances, consistent with previous studies.