ILLUMINATING THE PRIMEVAL UNIVERSE WITH TYPE IIn SUPERNOVAE

The detection of Population III (Pop III) supernovae (SNe) could directly probe the primordial initial mass function for the first time, unveiling the properties of the first galaxies, early chemical enrichment and reionization, and the seeds of supermassive black holes. Growing evidence that some Pop III stars were less massive than 100 M-circle dot may complicate prospects for their detection, because even though they would have been more plentiful, they would have died as core-collapse SNe, with far less luminosity than pair-instability explosions. This picture greatly improves if the SN shock collides with a dense circumstellar shell ejected during a prior violent luminous blue variable type eruption. Such collisions can turn even dim SNe into extremely bright ones whose luminosities can rival those of pair-instability SNe. We present simulations of Pop III Type IIn SN light curves and spectra performed with the Los Alamos RAGE and SPECTRUM codes. Taking into account Ly alpha absorption in the early universe and cosmological redshifting, we find that 40 M-circle dot Pop III Type IIn SNe will be visible out to z similar to 20 with the James Webb Space Telescope and out to z similar to 7 with WFIRST. Thus, even low mass Pop III SNe can be used to probe the primeval universe.