The Radio Signatures of the First Supernovae
  Primordial stars are key to primeval structure formation as the first stellar
components of primeval galaxies, the sources of cosmic chemical enrichment and
likely cosmic reionization, and they possibly gave rise to the supermassive
black holes residing at the centres of galaxies today. While the direct
detection of individual Pop III stars will likely remain beyond reach for
decades to come, we show their supernova remnants may soon be detectable in the
radio. We calculate radio synchrotron signatures between 0.5 - 35 GHz from
hydrodynamical computations of the supernova remnants of Pop III stars in
minihaloes. We find that hypernovae yield the brightest systems, with observed
radio fluxes as high as 1 - 10 muJy. Less energetic Type II supernovae yield
remnants about a factor of 30 dimmer and pair-instability supernova remnants
are dimmer by a factor of more than 10,000. Because of the high gas densities
of the progenitor environments, synchrotron losses severely limit the maximum
emission frequencies, producing a distinctive peaked radio spectrum
distinguishable from normal galactic supernova remnant spectra. Hypernovae
radio remnants should be detectable by existing radio facilities like eVLA and
eMERLIN while Type II supernova remnants will require the Square Kilometre
Array. The number counts of hypernova remnants at z > 20 with fluxes above 1
muJy are expected to be one per hundred square degree field, increasing to a
few per square degree if they form down to z = 10. The detection of a z > 20
Type II supernova remnant brighter than 1 nJy would require a 100 - 200 square
degree field, although only a 1 - 2 square degree field for those forming down
to z = 10. Hypernova and Type II supernova remnants are easily separated from
one another by their light curves, which will enable future surveys to use them
to constrain the initial mass function of Pop III stars.
