The Number of Supernovae from Primordial Stars in the Universe

Recent simulations of the formation of the first luminous objects in theuniverse predict isolated very massive stars to form in dark matter halos withvirial temperatures large enough to allow significant amounts of molecularhydrogen to form. We construct a semi-analytic model based on thePress-Schechter formalism and calibrate the minimum halos mass that may form aprimordial star with the results from extensive adaptive mesh refinementsimulations. The model also includes star formation in objects with virialtemperatures in excess of ten thousand Kelvin. The free parameters are tuned tomatch the optical depth measurements by the WMAP satellite. The modelsexplicitly includes the negative feedback of the destruction of molecularhydrogen by a soft UV background which is computed self-consistently. Wepredict high redshift supernova rates as one of the most promising tools totest the current scenario of primordial star formation. The supernova rate fromprimordial stars peaks at redshifts ~20. Using an analytic model for theluminosities of pair-instability supernovae we predict observable magnitudesand discuss possible observational strategies. Such supernovae would releaseenough metals corresponding to a uniform enrichment to a few hundred thousandsof solar metalicity. If some of these stars produce gamma ray bursts our rateswill be directly applicable to understanding the anticipated results from theSWIFT satellite. This study highlights the great potential for the James Webbspace telescope in probing cosmic structure at redshifts greater than 20.Comment: 12 pages, 8 figures, submitted to Astrophysical Journa