How the Population III Initial Mass Function Governs the Properties of
  the First Galaxies
  The properties of Population III (Pop III) stars impact many aspects of
primeval structure formation such as the onset of cosmological reionization and
early chemical enrichment. However, in spite of over twenty years of numerical
simulations and attempts to constrain the Pop III initial mass function (IMF)
by stellar archaelogy, little is known of the masses of the first stars for
certain. Here, we model the effect of Pop III IMF on the properties of primeval
galaxies with a suite of high-resolution radiation-hydrodynamical simulations
with ENZO. We find that a top-heavy Pop III IMF results in earlier star
formation but dimmer galaxies than a more conventional Salpeter-type IMF
because explosions of massive Pop III stars produce more turbulence that
suppresses high-mass second-generation star formation. Our models suggest that
the Pop III IMF could therefore be inferred from detections of primordial
galaxies, which will be principal targets of the James Webb Space Telescope and
extremely large telecopes on the ground in the coming decade.
