Radiative and Kinetic Feedback by Low-Mass Primordial Stars
  Ionizing UV radiation and supernova flows amidst clustered minihalos at high
redshift regulated the rise of the first stellar populations in the universe.
Previous studies have addressed the effects of very massive primordial stars on
the collapse of nearby halos into new stars, but the absence of the odd-even
nucleosynthetic signature of pair-instability supernovae in ancient metal-poor
stars suggests that Population III stars may have been less than 100
M$_{\odot}$. We extend our earlier survey of local UV feedback on star
formation to 25 - 80 M$_{\odot}$ stars and include kinetic feedback by
supernovae for 25 - 40 M$_{\odot}$ stars. We find radiative feedback to be
relatively uniform over this mass range, primarily because the larger fluxes of
more massive stars are offset by their shorter lifetimes. Our models
demonstrate that prior to the rise of global UV backgrounds, Lyman-Werner
photons from nearby stars cannot prevent halos from forming new stars. These
calculations also reveal that violent dynamical instabilities can erupt in the
UV radiation front enveloping a primordial halo but that they ultimately have
no effect on the formation of a star. Finally, our simulations suggest that
relic H II regions surrounding partially evaporated halos may expel
Lyman-Werner backgrounds at lower redshifts, allowing stars to form that were
previously suppressed. We provide fits to radiative and kinetic feedback on
star formation for use in both semianalytic models and numerical simulations.
