We present spectroscopic data for individual stars observed from 2004 March through 2008 August as part of our Michigan/MIKE Fiber System ( MMFS ) survey of four dwarf spheroidal ( dSph ) galaxies : Carina , Fornax , Sculptor and Sextans .
Using MMFS at the Magellan/Clay Telescope at Las Campanas Observatory , we have acquired 8855 spectra from 7103 red giant candidates in these Galactic satellites .
We list measurements of each star ’ s line-of-sight velocity ( median error \pm 2.1 km s ^ { -1 } ) and spectral line indices for iron and magnesium absorption features .
We use globular cluster spectra to calibrate the indices onto standard [ Fe/H ] metallicity scales , but comparison of the resulting metallicities with published values suggests that the MMFS indices are best used as indicators of relative , not absolute metallicity .
The empirical distributions of velocity and spectral indices also allow us to quantify the amount of contamination by foreground stars .
In a companion paper we develop an algorithm that evaluates the membership probability for each star , showing that the present MMFS sample contains more than 5000 dSph members , including 774 Carina members , 2483 Fornax members , 1365 Sculptor members , and 441 Sextans members .