A new set of very high signal-to-noise ( S / N > 100 / 1 ) , medium-resolution ( R \sim 3000 ) optical spectra have been obtained for 302 of the candidate “ weak-metal ” stars selected by Bidelman & MacConnell .
We use these data to calibrate the recently developed generalization of the SEGUE Stellar Parameter Pipeline , and obtain estimates of the atmospheric parameters ( T _ { eff } , log g , and [ Fe/H ] ) for these non-SDSS/SEGUE data ; we also obtain estimates of [ C/Fe ] .
The new abundance measurements are shown to be consistent with available high-resolution spectroscopic determinations , and represent a substantial improvement over the accuracies obtained from the previous photometric estimates reported in Paper I of this series .
The apparent offset in the photometric abundances of the giants in this sample noted by several authors is confirmed by our new spectroscopy ; no such effect is found for the dwarfs .
The presence of a metal-weak thick-disk ( MWTD ) population is clearly supported by these new abundance data .
Some 25 % of the stars with metallicities -1.8 < [ Fe/H ] \leq - 0.8 exhibit orbital eccentricities e < 0.4 , yet are clearly separated from members of the inner-halo population with similar metallicities by their location in a Lindblad energy vs. angular momentum diagram .
A comparison is made with recent results for a similar-size sample of RAVE stars from Ruchti et al .
We conclude , based on both of these samples , that the MWTD is real , and must be accounted for in discussions of the formation and evolution of the disk system of the Milky Way .