Stellar winds and metal enrichment from fast-rotating Population III
  stars
  Stellar winds from fast-rotating Population III (Pop III) stars have long
been suspected to make important contributions to early metal enrichment, as
features in the nucleosynthesis of such `spinstars' are consistent with the
chemical abundance patterns of some metal-poor stars in the local Universe.
Particularly, stellar winds rich in light elements can provide another pathway
towards explaining the carbon enhancement in carbon-enhanced metal-poor (CEMP)
stars. In this work, we focus on the feedback of Pop III stellar winds combined
with supernovae (SNe), and derive the resulting chemical signatures in the
enriched medium. We explore a large parameter space of Pop III star formation,
feedback, yields from winds and SNe with a semi-analytical model. The predicted
pattern of carbon and iron abundances of second-generation stars agrees well
with observations of CEMP-no stars ($[\rm Ba/Fe]<0$) at $[\rm Fe/H]\lesssim -3$
and $A(\mathrm{C})\lesssim 7$, under the optimistic assumption of significant
mass loss by winds from massive ($\gtrsim 25\ \rm M_{\odot}$) stars that
collapse into BHs without SNe. In this scenario, carbon-rich but iron-free
second-generation stars can form in systems dominated by enrichment from winds,
gaining trace amounts of iron by accretion from the interstellar medium, to
become the most iron-poor and carbon-enhanced stars seen in observations ($[\rm
Fe/H]\lesssim -4$, $[\rm C/Fe]\gtrsim 2$). We conclude that the observed
CEMP-no stars can be explained by both our winds + ISM accretion channel as
well as the well-studied faint SN scenario. Wind feedback from Pop~III
spinstars deserves more detailed modelling in early cosmic structure formation.
