Title: Stellar Abundances for Galactic Archaeology Database IV - Compilation of Stars in Dwarf Galaxies,
Abstract: We have constructed the database of stars in the local group using the
extended version of the SAGA (Stellar Abundances for Galactic Archaeology)
database that contains stars in 24 dwarf spheroidal galaxies and ultra faint
dwarfs. The new version of the database includes more than 4500 stars in the
Milky Way, by removing the previous metallicity criterion of [Fe/H] <= -2.5,
and more than 6000 stars in the local group galaxies. We examined a validity of
using a combined data set for elemental abundances. We also checked a
consistency between the derived distances to individual stars and those to
galaxies in the literature values. Using the updated database, the
characteristics of stars in dwarf galaxies are discussed. Our statistical
analyses of alpha-element abundances show that the change of the slope of the
[alpha/Fe] relative to [Fe/H] (so-called "knee") occurs at [Fe/H] = -1.0+-0.1
for the Milky Way. The knee positions for selected galaxies are derived by
applying the same method. Star formation history of individual galaxies are
explored using the slope of the cumulative metallicity distribution function.
Radial gradients along the four directions are inspected in six galaxies where
we find no direction dependence of metallicity gradients along the major and
minor axes. The compilation of all the available data shows a lack of CEMP-s
population in dwarf galaxies, while there may be some CEMP-no stars at [Fe/H]
<~ -3 even in the very small sample. The inspection of the relationship between
Eu and Ba abundances confirms an anomalously Ba-rich population in Fornax,
which indicates a pre-enrichment of interstellar gas with r-process elements.
We do not find any evidence of anti-correlations in O-Na and Mg-Al abundances,
which characterises the abundance trends in the Galactic globular clusters.