Compact Stellar Binary Assembly in the First Nuclear Star Clusters and
  r-Process Synthesis in the Early Universe
  Investigations of elemental abundances in the ancient and most metal
deficient stars are extremely important because they serve as tests of variable
nucleosynthesis pathways and can provide critical inferences of the type of
stars that lived and died before them. The presence of r-process elements in a
handful of carbon-enhanced metal-poor (CEMP-r) stars, which are assumed to be
closely connected to the chemical yield from the first stars, is hard to
reconcile with standard neutron star mergers. Here we show that the production
rate of dynamically assembled compact binaries in high-z nuclear star clusters
can attain a sufficient high value to be a potential viable source of heavy
r-process material in CEMP-r stars. The predicted frequency of such events in
the early Galaxy, much lower than the frequency of Type II supernovae but with
significantly higher mass ejected per event, can naturally lead to a high level
of scatter of Eu as observed in CEMP-r stars.
