To compare the chemistries of stars in the Milky Way dwarf spheroidal satellite galaxies ( dSph ) with stars in the Galaxy , we have compiled a large sample of Galactic stellar abundances from the literature .
When kinematic information is available , we have assigned the stars to standard Galactic components through Bayesian classification based on Gaussian velocity ellipsoids .
As found in previous studies , the [ \alpha /Fe ] ratios of most stars in the dSph galaxies are generally lower than similar metallicity Galactic stars in this extended sample .
Our kinematically selected stars confirm this for the Galactic halo , thin disk , and thick disk components .
There is marginal overlap in the low [ \alpha /Fe ] ratios between dSph stars and Galactic halo stars on extreme retrograde orbits ( V < -420 km s ^ { -1 } ) , but this is not supported by other element ratios .
Other element ratios compared in this paper include r- and s-process abundances , where we find a significant offset in the [ Y/Fe ] ratios that result in a large overabundance in [ Ba/Y ] in most dSph stars compared to Galactic stars .
Thus , the chemical signatures of most of the dSph stars are distinct from the stars in each of the kinematic components of the Galaxy .
This result rules out continuous merging of low mass galaxies similar to these dSph satellites during the formation of the Galaxy .
We do not rule out very early merging of low mass dwarf galaxies though , since \leq 1/2 of the most metal-poor stars ( [ Fe/H ] \leq - 1.8 ) have chemistries that are in fair agreement with Galactic halo stars .
We also do not rule out merging with higher mass galaxies , although we notice that the LMC and the remnants of the Sgr dwarf galaxy are also chemically distinct from the majority of the Galactic halo stars .
Formation of the Galaxy ’ s thick disk by heating of an old thin disk during a merger is also not ruled out , however the Galaxy ’ s thick disk itself can not be comprised of the remnants from a low mass ( dSph ) dwarf galaxy , nor a high mass dwarf galaxy like the LMC or Sgr , due to differences in chemistry .

The new and independent environments offered by the dSph galaxies also allow us to examine fundamental assumptions related to the nucleosynthesis of the elements .
The metal-poor stars ( [ Fe/H ] \leq - 1.8 ) in the dSph galaxies appear to have lower [ Ca/Fe ] and [ Ti/Fe ] than [ Mg/Fe ] ratios , unlike similar metallicity stars in the Galaxy .
Predictions from the \alpha -process ( \alpha -rich freeze out ) would be consistent with this result if there have been a lack of hypernovae in dSph galaxies .
The \alpha -process could also be responsible for the very low Y abundances in the metal-poor stars in dSphs ; since [ La/Eu ] ( and possibly [ Ba/Eu ] ) are consistent with pure r-process results , then the low [ Y/Eu ] suggests a separate r-process site for this light ( first peak ) r-process element .
We also discuss SNe II rates and yields as other alternatives though .
In stars with higher metallicities ( [ Fe/H ] \geq - 1.8 ) , contributions from the s-process are expected ; [ ( Y , La , & Ba ) /Eu ] all rise as expected , and yet [ Ba/Y ] is still much higher in the dSph stars than similar metallicity Galactic stars .
This result is consistent with s-process contributions from lower metallicity AGB stars in dSph galaxies , and is in good agreement with the slower chemical evolution expected in the low mass dSph galaxies , relative to the Galaxy , such that the build up of metals occurs over much longer timescales .
Future investigations of nucleosynthetic constraints ( as well as galaxy formation and evolution ) will require an examination of many stars within individual dwarf galaxies .

Finally , the Na-Ni trend reported by Nissen & Schuster ( 1997 ) is confirmed in Galactic halo stars , but discuss this in terms of the general nucleosynthesis of neutron rich elements .
We do not confirm that the Na-Ni trend is related to the accretion of dSph galaxies in the Galactic halo .