The Number of Supernovae from Primordial Stars in the Universe

We explore the consequences of radiative feedback on early generations of star formation. The main cooling mechanism in primordial star formation is from rotational line emission of molecular hydrogen. However, copious amounts of UV photons produced by these first massive stars effectively dissociate H₂. A consequence of this negative radiative feedback is to raise the required halo mass that can form a primordial star within it. Using results from Eulerian AMR cosmological hydrodynamics simulations, we construct a semi‐analytic method to trace the minimum mass of a dark matter halo required to form stars as a function of redshift. Provided this minimum mass, Press‐Schechter formalism allows us to calculate the density of these halos and predict Pop III SNe rates. We present preliminary results for the differential and total SNe rates per sky area. If a fixed fraction of these supernovae would also lead to long duration gamma ray bursts, our results can be scaled appropriately. We also compute the evolution of the metallicity of the IGM from supernovae of primordial stars alone. If the first stars die in pair instability supernovae the metals they expelled could pre‐enrich the IGM to an average as high as one ten‐thousandth of solar metallicity.