Copyright by Athena Ranice Stacy 2011 - The University of Texas at ...

current computational limits.
If radiative feedback were typically able to prevent Pop III stars from
growing to more than a few tens of solar masses, this would have several effects
on their observational signatures. PISNe would be less frequent, as this re-
quires a star to grow to greater than 140 M⊙. Old, metal-poor stars within the
Milky Way halo and nearby dwarf galaxies may preserve the nucleosynthetic
pattern of the first SNe, so this may help to explain the lack of PISNe chemical
signatures found in these nearby stars (e.g. Christlieb et al. 2002; Beers and
Christlieb 2005; Frebel et al. 2005; Tumlinson 2006; but see Karlsson et al.
2008). Instead, Pop III stars may end their lives through core-collapse SNe or
direct collapse to BHs. For sufficient stellar rotation rates, the possibility of
Pop III collapsar GRBs also remains (e.g. Stacy et al. 2011). The feedback of
Pop III stars on their neighboring metal-free minihalos would also be altered,
though the details of how the mass and formation rate of such ‘Pop III.2’ stars
would be affected remains to be determined by future simulations.
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