Rotation and Internal Structure of Population III Protostars
  We analyze the cosmological simulations performed in the recent work of Greif
et al. (2012), which followed the early growth and merger history of Pop III
stars while resolving scales as small as 0.05 R_sol. This is the first set of
cosmological simulations to self-consistently resolve the rotation and internal
structure of Pop III protostars. We find that Pop III stars form under
significant rotational support which is maintained for the duration of the
simulations. The protostellar surfaces spin from ~50% to nearly 100% of
Keplerian rotational velocity. These rotation rates persist after experiencing
multiple stellar merger events. In the brief time period simulated (~ 10 yr),
the protostars show little indication of convective instability, and their
properties furthermore show little correlation with the properties of their
host minihaloes. If Pop III protostars within this range of environments
generally form with high degrees of rotational support, and if this rotational
support is maintained for a sufficient amount of time, this has a number of
crucial implications for Pop III evolution and nucleosynthesis, as well as the
possibility for Pop III pair-instability supernovae, and the question of
whether the first stars produced gamma-ray bursts.
