We discuss a 175 deg ^ { 2 } spectroscopic survey for blue horizontal branch ( BHB ) stars in the Galactic halo .
We use the Two Micron All Sky Survey ( 2MASS ) and the Sloan Digital Sky Survey ( SDSS ) to select BHB candidates , and find that the 2MASS and SDSS color-selection is 38 % and 50 % efficient , respectively , for BHB stars .
Our samples include one likely run-away B7 star 6 kpc below the Galactic plane .
The global properties of the BHB samples are consistent with membership in the halo population : the median metallicity is [ Fe/H ] = -1.7 , the velocity dispersion is 108 km s ^ { -1 } , and the mean Galactic rotation of the BHB stars 3 < |z| < 15 kpc is -4 \pm 30 km s ^ { -1 } .
We discuss the theoretical basis of the Preston , Shectman & Beers M _ { V } -color relation for BHB stars , and conclude that intrinsic shape of the BHB M _ { V } -color relation results from the physics of stars on the horizontal branch .
We calculate the luminosity function for the field BHB star samples using the Efstathiou , Ellis , & Peterson maximum-likelihood method which is unbiased by density variations .
The field BHB luminosity function exhibits a steep rise at bright luminosities , a peak between 0.8 < M _ { V } < 1.0 , and a tail at faint luminosities .
We compare the field BHB luminosity functions with the luminosity functions derived from sixteen different globular cluster BHBs .
Kolmogorov-Smirnov tests suggest that field BHB stars and BHB stars in globular clusters share a common distribution of luminosities , with the exception of globular clusters with extended BHBs .