  An overview of the sources for heavy elements in the early Galaxy is given.
It is shown that observations of abundances in metal-poor stars can be used
along with a basic understanding of stellar models to guide the search for the
source of the heavy r-process nuclei (r-nuclei). Observations show that this
source produces very little of the elements from C through Zn including Fe.
This strongly suggests that O-Ne-Mg core-collapse supernovae (SNe) from
progenitors of ~8-11M_sun are the source for the heavy r-nuclei. It is shown
that a two-component model based on the abundances of Fe (from Fe core-collapse
SNe) and Eu (from O-Ne-Mg core-collapse SNe) gives very good quantitative
predictions for the abundances of all the other elements in metal-poor stars.
